MK1 Yaris: power steering/body roll/seating position

[Kikiriki]

Hello!
I'm a newcomer to the Toyota world. Before I use to drive 2000s Alfa Romeos but have been recently put on to toyotas (by a friend who is absolutely crazy about his 2zz-ge corolla).
I like the 2003 2sz-fe Yaris because it's nimble, rotates good off throtle even stock and is very cheap to run. My friends and I like to do time attack runs on rural (but paved) closed roads and am in need of some assistance in regards to modifications.

Firstly I'd love to solve my problem with the "suggestion wheel". The steering feels really vague and numb. Is there a way to disable the electric power steering without any fault codes / is there a good fit for a shorter steering rack that I could swap in?

Secondly, how do I reduce body roll. I run eibach lowering springs, japan parts shock absorbers and new oem front sway bar linkages. Does a rear sway bar kit help? I'd like to reduce body roll but at the same time not make the car more oversteery, because it allready dances pretty well.

Thirdly, is there a way to lower seating position?

Thanks to anyone that reads/replies to this and shares their knowledge!
Hello from the coast of Slovenia:)