12 psi will be fine, but you may want to check that its not leaning out at all. Upgrading your fuel pump is always a good idea when running more boost. Probably wouldn't go too much higher than that until you have some other bits and pieces to support it.
Yep thats right Cause the R32's are 2 litres, they run 10 psi to make up for the smaller capacity. By changing to the RB20 wastegate actuator, you are getting 10 psi instead of 7 psi. This is a lot better than a boost controller as there is no chance of boost spikes, therefore safer for your turbo. You still need to ground that one wire to get rid of the two stage boost, and then bypass the solenoid. There is a tutorial somewhere here on SAU