EGR, Boost, EGT advice PLEASE

Hi fellas I really need some advice/ information here please.

The Car- 03 Patrol wagon, TD42 intercooled. Motor is stock 201xxx. 3 inch exhaust with box. Soon to include a catch can. running 4" lift 35" tyres. About to put 4.11 diff gears. ETG gauge and boost gauge. soon to have variable boost controller. EGTs get to 450 max iv seen and boost at 9PSI.

Q1- I wonna wind up boost to around 15psi. a stock motor should handle that hay ??

Q2- I need to wind a bit more fuel just not confident on which screw is for idle ect... ( No forums show a clear pic).

Q3- there are two small vacuum controlled valves that are for the EGR setup. Even the Manuel doesn't describe how they work or how to adjust them. there's a third lil electronic solenoid there that I don't know about either??

Any help fellas would be muchly appreciated. once I get the car set up a bit smooth I will get LMG performance (warnertown SA) to have a look for me. I just like to know what's going on myself, as I do a few long trips, after reliability not so much power.

will post a few pics of egr valves when I get back home.
Cheers