They are open to drop some features apparently, but maybe not “90%”

The developers are taking a “less is more” approach. This means that some features of the original sudo may not be reimplemented if they serve only niche, or more recently considered “outdated” practices.

tldr is great, sometimes you can’t remember the exact syntax for a certain command and just need a quick reminder as well.

Can I mod games as freely and as easily as I do on Windows?

It depends a lot on the game, but in my experience not always. Running games straight from steam works really well with a small number of exceptions, but a lot of the sometimes weird tools for patching exe:s and so on that some games use can sometimes be a pain to get running. Not necessarily impossible but yeah this is a reason for why I still keep around my windows installation for dual booting.

If you want to test windows programs on linux, you’re probably going to want to do that in a virtual machine, or even a spare computer just for testing on windows. Depending on how much you need to use excel, a virtual machine could be a good option for that as well, but if using Microsoft Excel™ is a big part of your job, maybe it makes more sense to just stay on Windows for work at least