Most of the time with using after maker pistons you will have to bend the factory oil squirters or trade them out for a newer version. It is always best to replace the crush washers when removed.
Yes the 22mm wrist pins and a little stronger. Really just depends on your built plans on if you need to make a investment like that. Normally you would buy new rods with a 6 bolt bottom and a 7 bolt top and then yes run a 7 bolt piston.
Yes that is very possible and leak that is created after a maf sensor is unmetered air that the ecu can't compensate for with fuel so it creates a lean condition.
It's that the fuel pump is over heating then. The fuel that's in the tank is what helps keep the pump cool. Unless someone makes something to help keep the pump cool aftermarket it sounds like you will just have to keep more than a half tank in the car unless you want to change to a frame mount...
When does the issue happen? Is it after driving or just when it's hot outside? A fuel pump that over heats can cause an issue if it cavitaes or if it doesn't have a strong enough ground circuit.
The bolt or stud will be the same thread pitch so in order to fix that hole you will most likely need to use a tap and Heli coil it. For the other part of the running issue check the spark plugs and make sure they are good. I have had my 4g63 idle good but break up over 3000 rpm because of the...