2. Dagger in MH and mace in OH or daggers in both slots?
Probably dagger, as you're loom geared everything will die in an ambush followed up by Eviscerate anyway
3. How do I counteract druid rejuvenation spam?
Stealth -> sap -> go away. Healers are OP at low levels, PvP isn't balanced for it
4. As a subtlety rogue, what should I be doing in WSG and AB?
WSG -> nuke EFC down, sap people, try to peel off your efc.
AB -> cap flags, all day long, steal those undefended bases
On number 2, sure, ambush hits high, but only when it crits. I have had a 1700 crit with darkmoon firewater+ berserk+blood fury, but that was the only time I have one shotted someone. Also, do you mind clarifying "probably dagger?" Did you mean daggers in both hands?