My trackpad is pretty bad and I generally enjoy using mouse a lot more, so I guess my answer is mouse. I use Razer Atheris at 2400 dpi, it's a good mouse if you travel a lot (for example, I take it to uni sometimes), it's also pretty heavy, which I like, and is one of the cheapest Razer mice.
here https://scratch.mit.edu/projects/389464290/ :) if you're new to Scratch, you won't be saved in the in-game leaderboard, because you need "Scratcher" rank to use cloud variables (I guess the reason this speedrun.com leaderboard was created in the first place is to let people who don't have that rank compete in Scratch Getting Over It speedrunning)
I think it's true that the current categories are pretty much the same. An all skips category would be a great addition imo.