About starting areas, I really loved Serpent Spine(live) and Kunark(Vaniki level locked), all "classic" areas seems shit IMO, with lot of low density areas with ambushes and high level mobs mixed with low level mobs, making finding an enemy a chore... Qeynos is the lesser evil which I played. Blackburrow, I honestly din't liked much the potential to get "trains" there, but the ruins on north of Qeynos Hills are great.
For those who wonder how much better necros become from lv 11 to 12, the best necro dot at lv 11 is poison bolt which would dishes 6+
(5*7 tiks) damage or 41 damage (yes, no new offensive spells at lv 8 save a undead only spell), Heat Blood at this level will deal 17*6 tiks = 102 damage and the enemy has -100 to resist making resist extremely unlikely. The snare also becomes more than 2x more effective. Not even Wizards have increments of over 2x damage after getting a new spell "tier".
The unique thing which doesn't scale that much is their "pets", Emissary of Thule max damage is 61 * 3 (attacks per tik) = 183. It will not outDPS your DoTs, but helps a bit.
And in live, necromancers are even stronger. You get spells earlier and they are stronger than in p99...