MFR kicks butt, I don't know why forestgrind would ever be high on somebody's priority list. I really wish you did give more than "..." because I really want to know. It's always felt like it makes much more work than it relieves you of.
Thaumcraft is very insulated from any other mod. It would overshadow Witchery and everything else. Instead of playing "Attack of the B-Team" you'd be playing "Thaumcraft and some other things".
I do agree about the power generation problem. I would adore this pack if it had bigreactors and computercraft to manage them.
Iron Chests might be nice. With the resource abundance, the materials for Strongboxes aren't so hard to come by though and I hear they have quite good storage.
Final note, I would like biplanes added to Flan's mod. The parts are there taunting me, but I can't put them together.