I have a 2004 stock sti with TBE i purchased and need some info about some repairs i am going to attempt?

i have an oil leak coming from my valve covers on both sides i believe there is quite a bit of oil leakin on the bottom half of the motor... dripping onto my exhaust. so how hard is it to replace the seals on the valve covers? since its such a tight fit do i have to pull the motor?

2nd i have a power steering leak i am pretty sure i will be replacing the rack and pinion assembly how hard it that job?

3rd for some strange reason when i bought the car its very hard to fill up with gas it just has to be filled up at an extremely low rate something with fill tube maybe? i know there was a broken plug for some type of cannister in the rear of my car it was throwing a check engine light i fixed the cable but it still wont fill up? any ideas on this one.... i cannot seem to find a solution

the car has 155k on it i would like to also do a refresh on the engine timing belt .. seals...what all needs to be done for a engine refresh?

and if im going to pull the motor that is the time i would like to upgrade the turbo and whatever mods i make to the engine i want to do it all at once then get er turned. any input for mods?