Your initial problem sounds like it is resolved then?
The results you are getting from WordPress could be due to various factors.
First, when you reduce the size of an image in AP, either using Resize Document or Export, you're going to be working with resampling. Depending on what option (Bicubic, etc) you choose, you will get different results in how your final image looks..
As for uploading to Wordpress, it depends on a few more things. Your theme could be display the image you uploaded directly, and let the browser resize it on the fly. Alternatively, some themes might generate thumbnails for various uses in the theme (which might not necessarily be tiny), and this re-saving process could again change the quality of the final image.
If you want to keep things simple I suggest resizing it and making sure you get the quality you want before inserting it into WP. And when you are importing the image in WP, just make sure the image is display at "full size" so it simply display the uploaded image.