1. I trigger to middle stump and sometimes off which opens up the leg side for me. It actually makes it difficult to play on the off side if the line is middle/off/close to off.
2. My trigger is complete before the ball is released which means that I am still (head and feet) at the point of release.
3. My observation is that trigger works best against a swinging and quick delivery. For a slow/medium bowler, my trigger actually throws off my line. Against a slow/medium I do a very small or no trigger. I do recommend doing a trigger against a left-arm fast/medium bowler from over the wicket. The trigger (angled) helps me get in line better to line up my drives.
4. I am also experimenting with no forward press against spinners. So far in nets, this approach has resulted in some very clean hits. I can hit with a forward press as well but its just too much work sometimes and I need my legs by the time I get to the spinners.