Fr. Frank gave you a great answer on how to set engine trim. With my old 20" shaft motor on the transom, I found engine trim had little effect on the boat's running angle, and I generally just trimmed it out as far as possible to minimize drag of the lower unit. Now with the 25" shaft motor on a bracket with 30" setback, the motor evidently has much more leverage because engine trim now has a big effect on running angle and that's my primary control for running angle. One note of caution - In following seas, you generally want the bow trimmed up (Motor and tabs up); the boat can get squirly and hard to handle if the bow is trimmed down in those conditions.
Regarding trim tabs, the more you lower them, the more drag they'll cause, so I normally try to minimize their use, but when it gets rough enough, I quit worrying about gas mileage and use them as required to improve ride! How soon that happens depends on how high your threshold of pain is!
Deep-V's tend to lean into the wind (wind blows you off course, so when you crank in some rudder to correct, the boat heals over as it does anytime you turn the wheel). You will find that if your desired course has you running into the waves at anything other than directly head on, rolling the boat AWAY from the waves by just a few degrees, either by shifting gear around or using the tabs, will make a significant improvement in the ride. This is because you are essentially increasing the deadrise of the hull relative to the waves!
When you're in a short steep chop, like the 2' square waves common on the Bahama bank, you have 2 choices - either put 'er up on top at about 30-35 mph and just hit the tops of the waves, or trim everything down to min planing speed and slog along in comfort at 12-13 mph! If your boat isn't balanced well enough to plane that slow, you might want to consider a doelfin or equivalent and/or a good stern-lifting 4-blade prop. If none of that works, you may prefer the high speed approach!