If it's true that the misfires are limited to one bank and are random on that bank, indeed the +12 to the coils AND injectors are are good culprit. I would also not rule out the O2 sensor nearest the engine on that bank and also the VVT and associated components.
In my 30 years experience, weak ignition shows up at high cylinder pressures under high load. Bugged up fuel injectors usually result in bad idle and misfires at high RPMs.
What do the fuel trims look like on that bank? An exhaust leak before the first 02 sensor and cat will richen the mixture causing large fuel +fuel trims (since the 02 sensor is reading too much oxygen, the computer adds fuel). If it gets over 20% extra or so a code will be set.
And another thought, the dreaded alternator difficulty with these cars can cause all kinds of problems. Usually i see cam position problems, but who knows what else it can effect.
Sorry for your problems, but this is a good thread. Please keep us posted.