1 and 2. Those flat stats are waaaaaay better than the procs of the other trinkets.
For raid....well, depends of your mana problem. If you had serious mana problem then take the spider one (an use and for 10s you recover mana).
As i said, no idea for holy, but as discipline I have SERIOUS mana problems on certain bosses hahahaa, so will change one of the flat stats trinkets by something that gives mana