I have Affinity Designer, but I rarely use it. I don’t have Illustrator.
Photoshop is just the tool I’m comfortable with and there’s the artboards feature, which I don’t know if AD or AI have? That makes it super easy to see all images in a single project, but also export them at once.
Yes, but you can still import vector files that are editable outside Photoshop. And as long as your original files are big enough to begin with, I don’t see it as an issue that it is raster. I tend to use vector only for things that I’m sure I will eventually need to resize. In this case, I don’t think a forum logo will ever need to be 5000px tall or wide, for example.