Going to be a a$$, but if you don't know what you're doing to the point of not being able to figure out how to adjust the wastegate perhaps you shouldn't be messing with boost/fuel settings.... very very easy to blow your engine up there, do you have the money/means to deal with that?
All for customizing / modding stuff, but there's a certain degree of basic knowledge to be had first....
Immediate thoughts, 5 flats should give you a huge amount of smoke (as in double or more the amount of fuel).... probably you're either maxed out or the pump isn't all that great to begin with.
Wastegate shorten or lengthen depends on how exactly it's setup.... the smart thing to do is get a handheld vacuum/pressure pump and adjust it to open when you want. Or just disconnect and plug the line.
But, perhaps you should consider that there's limits to what these engines seem to be able to handle, and there's an inverse relationship on boost/power vs reliability (generalized). Sure you *can* likely run 15 psi on stock motor, but chances are good the head gaskets aren't staying there long.... 10 seems to be the generally accepted limit for a stock motor, and head studs are a very wise idea....