1) From what I recall vanguard gives a little prot vs whatever the hell is in power, I believe its strictly PC I could be wrong. It also protects somewhat against deathblow and rager powers, I believe its tied to the Veil, ala how spellbane fluctuates depending.

2) With my shifter here is what happened. With a warrior id get HP, occassionally parry attacks (you get an echo for this), retreat, dash and a few other things. When I enlivened stoneskin, haste, fly, pass door and control translucence they all got these, also when I worded they came with me. With a thief they can hide. If I remember correctly when bonded with a dwarf warrior I got 400ish HP it was pretty nuts.