Which class to pick for casual PVP-PVE gaming?

TL;DR: plan to play casually: a few hours a couple of days per week. Sometimes some PVE (heroics, maybe 10-ppl raids), sometimes probably BG (they work, right?). Nothing serious. What would be the best faction/class to pick for a casual gaming with minimal waiting in a line?

For PVE I assume I should be a healer or a tank, right? Do DD have long waiting time in LFG?

For PVE I should go with a horse for min waiting time?

PS: used to play on official servers through TBC and WOTLK as hunter, pala and mage. Really enjoyed frost mage in PVP and holy/port pala in PVE. Hunter was decent too but I had enough of it.

Definitely a druid, you can do everything and leveling as feral is super easy and quick as well. Queing as tank/heal is pretty quick, you can even get dungeon pops while u level. Horde is arguably the better pve faction as the racials favor them for pve