I will do a small batch 2-3liter wort for yeast starter is it enough to boil just 45min with a bit of hops in the beginning of the boil or should i do 60min boil?
I always throw in a small amount of hops as a safeguard against contamination. It's probably unnecessary, given usual sanitary practices, but it does provide an extra layer of security and, at the very least, peace of mind.
Hops do stress the yeast, but brewer's yeast should be rather well-adapted to hops, and it will have to be in the main batch anyways.