FE853

So I have a final edition Evo with 7k miles on it and I'm ready to mod it

the car is bone stock, before I get into the mods I want I need to know about modding so start there for me please.
I want to buy a Cobb AP V3 & run it on stage 0 map while the car is bone stock, then I'm gonna install the ETS V2 extreme exhaust along with a turbo smart BOV & an ETS intake all at once.

NOW, my questions is
1.Will running stage 0 map negatively affect my car?
2.After I install those parts listed above will I be able to tune it by myself with the access ports maps ?
3. if I can't tune it myself, I will go to a tuning shop, but can they tune my car through the access port so that if I ever want to remove said parts back to stock I can run the access port back to stage 0 map and it's like nothing happened ?

Im just very curious as to what/who is gonna tune my car cause I don't want it to run like **** after I install these parts

thanks guys