Mahrez will fight with Ozil, Ramsey, etc. Its not easy for him and i think the best for him is stay at leicester
He doesnt need to, he will be on the starting team no matter what. We could already guess arsenal's next season starting line up based on, if giroud hasnt been sold yet then he would be starter along with sanchez and mahrez as winger and ramsey and ozil as their midfielder , coaquelin as defensive midfielder
It could be possible if Wenger wish to change his lineup from last season and make a new set up for next season , which i think unlikely to be happen for Wenger style.
And what about Jack Wilshere , he already miss a lot last season , surely he gonna get a lot of play time next season. One thing for sure , Mahrez won't get guarantee starting line up , he gonna sitting bench for few times. Wish he have that consider before accept the offer from Arsenal.