If wanting a more painting/drawing app, I would go with Krita. GIMP is ok for photo manipulation, but be willing to add in plugins or create your own, the base program is lacking in my opinion.
For vector, I actually use Blender if my needs are simple with the Grease Pencil. Easily exported as an SVG when using Grease Pencil. I like Blender's toolset compared to Inkscape and man, do I not like the GTK UI toolkit. Plus I use Blender as a NLVE as well (strange I know, but since 2.8(I use 4.1 Beta), that has gotten a lot of love, certainly better compared to Kdenlive).
For layout, I would suggest Scribus.
Caldera is pretty much it for RIP. There was an open source project RIP project, but that has been dead since 2017 I think.
LED signage work, there are a couple of things, I'll have to go back and see if I can find those. I haven't messed much with that, but I know a few that have liked them that are local here. May try to see about asking them when I have the chance.
Word processing, I actually use neovim with some plugins, that definitely isn't going to be for everyone. Most should go to LibreOffice.
Thunderbird is a decent email client (although I worry about the maintenance of that project), I do use Kmail though, but I'm a big KDE user (my DE of choice on Arch is Plasma).
I know that there are some on here that make their own Macros for Draw, so for those that are into creating their own plugins for the above tools, tools that aid in that endeavour would be good (neovim for the win there as well)
