I use Strawberry for mine.

Are you referring to a drawing tablet? If so, then a good number of ones from the better known brands are supported by the kernel by default. Your safest bet though is Wacom. Wacom is definitely the best supported brand, but it tends to be more expensive than other brands (such as XP-pen and Huion). Non-Wacom branded tablets may require a little bit more initial configuration, like adding a udev rule (I had to do that for my Huion Inspiroy Ink).

In my experience larger packages (in terms of file space requirements) install slower, but download speed is a factor there too.

Cancelling compilation is safe to my knowledge. No changes were made as you stated. Just remember that the downloaded files will probably still be in your cache afterwards, so you may want to remove that with paccache.

You mention “partial installs,” but the actual issue is partial upgrades. A partial upgrade is when you don’t upgrade the entire system, but only one or more packages. A partial install isn’t really a term people use, but could probably refer to installing a package without its dependencies being installed.