Bhikkhu Pesala

Segoe UI Emoji is a COLR color font.
So when support was added for color emojis it also added support for other COLR fonts.
The support is not 100% as you cannot select a palette (if the font has more than the default),
and there is no support for changing the colors (even if the font supports it).
But COLR color fonts do work in Affinity apps now.
For example this was created in the current version of APub:

Ligatures in pasted text may be Alphabetic Presentation Forms ff, fi, fl, ffi, ffl, and not the decomposed text string ff, fi, fl, ffi, ffl. If they are, find and replace is the way to fix the problem as there is no OpenType feature enabled to turn off. 
Ligatures are enabled by default, but can be turned off from the Show Typography pane (Ctrl+Shift+T).

I downloaded the Linux font pack from Source Forge. 
I did not find a Linux Biolinum Caps font
The Linux Libertine Initials font contains small capitals, but no lowercase. I got the desired result by applying small capitals to Linux Biolinum and using Linux Libertine lowercase with Linux Libertine Initials. I use PagePlus X9, but Publisher would do the same. 
 

Ligatures in pasted text may be Alphabetic Presentation Forms ff, fi, fl, ffi, ffl, and not the decomposed text string ff, fi, fl, ffi, ffl. If they are, find and replace is the way to fix the problem as there is no OpenType feature enabled to turn off. 
Ligatures are enabled by default, but can be turned off from the Show Typography pane (Ctrl+Shift+T).

All installed fonts are available to Affinity Publisher. There is no need for it to do anything to make them available. What you need to do is download and install them.
I presume that MacOS is no different to Windows regarding this. 

My free fonts have superscripts and subscripts.
Superscripts are aligned with top of Cap Height Subscripts are aligned with the baseline Scientific inferiors bisect the baseline 

My free fonts have superscripts and subscripts.
Superscripts are aligned with top of Cap Height Subscripts are aligned with the baseline Scientific inferiors bisect the baseline 

Thank you Helge for that suggestion.
I would like to ask for another facility in Spelling:
to have a "Change All" option when checking spelling, so that if the same misspelling occurs multiple times in a document, you can change that misspelling throughout the whole document, wherever it occurs, with one single click.

Viewing the master pages and changing the margins there fixed the problem. I was somewhat surprised to see that the master page was still set to A4, after I hand changed the page to A5. 
This could be made more user-friendly, e.g. a checkbox to change spreads for master pages when changing them for the page. 

Hi Pesala
The only way I can get all the pages to change margins at the same time is via master page setup. I did try using the "selected spreads" option and selected all the spreads and only the spreads that I was on would change and not ALL. There does seem to be something not right with the spread setup dialogue option.

I changed it for the All spreads (but it's only a one page document).   

The proper way  to do this is to set a dot leader tab, not by using underscores. 

Many thanks - i'll get this logged 

Yes, I am using the latest beta. Try with the light interface, and you will see what the problem is. Pressing Tab does not highlight the next field for input. 

I don't understand what your problem is with always fault-finding. In PagePlus 1% condensed = -8% of tightening in Affinity Designer. 
Maybe that would be -10% if the frames were exactly the same width. I did not measure it, I just resized it to get the same line breaks.

There is a symbol for a forced line break.   If you are on a MAC, use Shift+Return and you will find a little blue arrow.  Don't know what it is on Windows.   As for your question No. 1 are you referencing tracking?    If so, you can define a tracking percentage using the Character Panel or in Text Styles.    Was this what you meant?

Agreed. The current steps are far too large. 

In PagePlus X9, the default stop is 1% for Alt+Left, and 0.1% for Ctrl+Alt+Left. 
I frequently use the latter for fine control applying it to the entire paragraph to prevent widows and orphans. Any negative kern value exceeding -3% is too tight, and should be avoided as far as possible. Often, I can reduce a paragraph by one line with just 0.1-0.5% of negative kerning. 
Default Spacing

1% Condensed

3% Condensed (Too tight)

I just tried resetting AF Publisher starting it holding down control. Now all is well. Thank you for your assistance. It is appreciated! 

Importing Word documents is bad practice when creating layouts. The carried over character attributes are known for causing various issues that can lead to a series of problems, including file corruption. You're better off creating a plain text document and reformatting it

Hi Pesala,

This is something that has been reported and passed on to development. I believe it should be fixed in the next build!

A drop list of memorized search and replace is fine. It would be fine too if those were some external text or XML files as the ones saved in different folders for different type of search by ID.
This way, it's easy to give  a "list" (some XML files) or replacements for specific works. And it's an easy way to store them away (or in a subfolder) until the next year when we'll need them.
For example I manage to reduce from 1 week to 1 day the formatting of a document with a list of ±35 "search and replace" with text and GREP. (Using script to do them in the proper order is even better). Hiding them in a subfolder is easy, or archiving them with the document would be better!
It's easy too, to give those files with the working document if someone else need it, or when working on another computer.
Another point: you can rename those files when needed, or (dupplicate them and) modify easily the regular expressions. That's faster than doing it again in the application.

InDesign’s GREP Builder looks remarkably similar to the Find and Replace dialogue in PagePlus.

Maybe another submenu could be added where users could store their most frequently used Regular Expressions. The drop list remembers about 20, but the one that I need often disappears from the bottom of the list. I spend some time finding the one that I want in my text file. It is all too easy to make an error and replace every occurrence of the letter e from your publication, or worse, replace something and not notice until it is too late to undo your mistake.
Ordinary users who do pick up the software once a month to publish their club Newsletter, are not likely to get far up the learning curve, and like me, will find it quicker to do things manually than to figure out what alchemy is required to automate the process.

InDesign’s GREP Builder looks remarkably similar to the Find and Replace dialogue in PagePlus.

Maybe another submenu could be added where users could store their most frequently used Regular Expressions. The drop list remembers about 20, but the one that I need often disappears from the bottom of the list. I spend some time finding the one that I want in my text file. It is all too easy to make an error and replace every occurrence of the letter e from your publication, or worse, replace something and not notice until it is too late to undo your mistake.
Ordinary users who do pick up the software once a month to publish their club Newsletter, are not likely to get far up the learning curve, and like me, will find it quicker to do things manually than to figure out what alchemy is required to automate the process.

There are millions of tutorials & examples on the web that can satisfy many/most cases. But there will always be a learning curve. People will always need to ask for help in situations they have trouble with.
Something akin to InDesign's GREP "builder" would be helpful though, as well as being able to save expressions for later use.

Each of those > symbols flyout for the actual choices in each category. However, even the above will not prevent people needing specific help in building an expression that works in their particular situation. A look on sites like the Adobe forums, the InDesign GREP Facebook group, StackOverflow, etc., will demonstrate even professionals need help. I frequently enough make mistakes when adapting expressions I find on the web, because of poor copy/pasting of expressions, editing existing expressions,  copying the wrong bits to the incorrect f or r fields, etc.
BTW, while I do not have a central text file for saving expressions, I do have a folder on my hard-drive with specific text files with the f/r expressions and sample text that I used them for. The files are named for what they do. 

PDF reader applications typically have a setting to enable "convert URLs to links" - so disable that if present.
Then you can see what APub has actually exported in the PDF.