thatFloozie

+1  I completely agree!
 
This is by far my biggest hangup with the program, for the exact reasons others have already explained. 
 
It negates the time savings/purpose of using shortcuts if you have to stop and think about how it will behave depending on certain circumstances, and then look over to double-check you have the tool you intended. 

@Mountainking that's not really isolation mode but hiding other layers.
 
At this point I have lost all faith in Designer. Even if this feature has been asked by many users, for years, it's not even in the roadmap.
 
https://forum.affinity.serif.com/index.php?/topic/842-affinity-designer-feature-roadmap/
 
Reading the roadmap thread it seems all progress in Designer is stalled. What a shame, it was a promising project.

Like Photoshop - fill the whole layer (or just a selection) with foreground or background color. [ ALT + BACKSPACE/DEL ] shortcut.

This is going to be tricky to explain - I hope this makes sense.
 
I would expect that if I set the Decimal Places for Unit Types on points, for example, to 0, that my stroke width options would be limited to whole numbers when I use the slider to select a stroke width. What actually happens is that the slider is just displaying the nearest whole number to the actual stroke width.
 
For example, I set my decimal limit to 0 in preferences, I drag the slider for stroke width to 1, and draw a rectangle. I would assume that the stroke of the rectangle is exactly 1 pt.  This is NOT the case.
 
If I switch the decimal limit to 6, I see that the actual stroke of my rectangle is something like 1.002345. This can also be clearly seen using the pixel grid. The stroke I thought was exactly 1 pixel is visibly wider than grid lines set to one pixel.
 
I discovered this while trying to make a checkerboard pattern. I couldn't figure out why my rectangles, snapped to the grid, with stroke set to 0, seemed to have gaps. When I changed the decimal places to 6, I discovered the rectangles actually had strokes of 0.000238. 
 
So unless you type a whole number instead of using the slider, you can never be certain that your stroke is exactly what you want it to be. Even with 6 decimal places, sliding the slider to 1 could still actually be something like 1.00000039865. This is very problematic for pixel-perfect exports, and negates the entire purpose of the slider bar.
 

Not exactly sure how to call this "feature" but I think in Illustrator it was called "Isolation Mode". 
 
What I want to be able to do is, for example, enter a group and drag a selection over a few elements without interfering with background elements. Without, obviously, having to lock them previously.
 
Is there something to accomplish this? It seems like a really basic feature and it's essential to my workflow. How do you guys deal with this type of situations?

+1  I completely agree!
 
This is by far my biggest hangup with the program, for the exact reasons others have already explained. 
 
It negates the time savings/purpose of using shortcuts if you have to stop and think about how it will behave depending on certain circumstances, and then look over to double-check you have the tool you intended. 

any 2 or more points, selected, describe part of an overall shape. Very useful to be able to copy and paste just that part of the curve or shape.

How about implementing a Illustrator like capability to quickly reposition the anchor point with holding spacebar? It adds so much speed to pen tool and should be an easy implement!

Selecting nodes – even more so nodes of more than one element – requires too many clicks/actions:
 
1) switch to the node tool
2) click on element A, now the nodes of the element show up
3) shift-click on any other element B, C and D
4) only now one can select individual nodes either by blocking or by marquee dragging
 
I suggest to skip step 2) and 3) so that when one uses the node tool selecting nodes works without having to activate a bezier element in the first place. (Hell, I’d even get rid of step 1 but that is another topic already discussed and overruled.)
 
That is the reason why one would switch to the node tool: to work on the nodes, right?

None of the apps currently does it, but Adobe’s apps do, and even OS X’s native screenshots tool (which is what I use in the example).

To put it simply, dragging a shape (like an ellipse in Designer or a marquee in Photo) should draw it (just as it does now), but when pressing ␣ (space bar) dragging should switch to moving the shape around (only while the space bar is pressed).