Looking at switching to Ubuntu, some questions

Hello everyone
Recently I have been contemplating switching to Linux, specifically Ubuntu, it looks the easiest to use and while I am technical, I simply cannot be bothered to fix things.
I do have some questions though before I make the switch which could potentially stop me from leaving Windows 10, as much as I want to switch to Linux, somethings you simply cannot leave behind.

So first and biggest is external GPU support, I use a Dell XPS 13 9360 Kaby Lake R system and a Gigabyte Aorus 1070 gaming box over thunderbolt 3, works rather well in Windows, seems to be mostly plug and play so far and I love this setup, it gives so much freedom!
Whats the chances of this working in Ubuntu? I don’t mind have to do a bit of initial configuration first but ideally in the long run for it to be plug and play, I need both loop back mode and external display modes to work.

I’ve recently started digital drawings also, i’m not tied to any software and I use a Wacom Intous, what would you recommend for application? I know the tablet works out of the box.
Same goes for photos, i’m not tied to any software and its only family photos and quick edits, I am thinking darktable as a free light room alternative, it looks rather good and should be decent for storing my library.

Next is things like Netflix and iTunes, this is purely for films, iTunes is used less and to be fair I will likely switching the TV/Films I have there to blu ray so I actually have them.
Is there an app for netflix that allows downloads like the Windows store one?

Finally is Office, I have a lot of things tied in here but nothing I don’t think can be adapted, I don’t use fancy formatting or anything like that, I am thinking of switching from one drive to something else, but not sure who or what.

Thats it really, again the egpu TB3 is a requirement, others are nice extras but not things that can stop me from leaving windows i believe.

Thoughts

Thanks

IDK the state of it right now, but from what I’ve heard, it wasn’t supported as of last year.

https://krita.org/en/

Netflix should work in Chrome or Firefox with enabled DRM.

Never heard of something like that, although I am not a Netflix user.

LibreOffice worked well for me in uni, I could use other people’s word docs and Excels and vice-versa.

You’d have to research that, but I wouln’t hold my breath.

Good luck.