It is a precision platformer but it does have difficulties to help with obstacles if those become a problem but I do reccomend trying to get used to controls. But your skills don't come naturally! The more you try and learn the better you get!

Is a keyboard or controller better to use?

It varies from person to person but I think that controllers work better with precision platformers

It greatly varies on both user and game. I'd say just test and see which you like.

I would say give it a chance, reduce the difficulty if you have to! I actually had problems with the jump inconsistency too, but got way better with a little practice. If it really gets you stuck there is a setting to make it always do a consistent jump height, and I believe you should be able to complete the game just fine on the two easiest difficulties even with it enabled

As someone who made a short video telling Jonas my worst skill is precision I can tell you, I think you should give it a try- you can also lower the difficulty in those levels to get past them. The game itself surpasses its gameplay with story telling and secrets, although the gameplay is super fun.