Re: pit trouble
You have to do something like 100 complete clears before you can expect results which are at least a bit statistically relevant. 8 runs aren't really much and it's not uncommon not to find a single unique. Even if you would, 95% of them are the usual mediocre stuff which you can as well find when visiting hell Mephisto a dozen times. The chance for uniques in the Pits or in the other high-level areas isn't higher than anywhere else, but there is a small chance that you find highest quality uniques.
Regarding MF, time is money and summon necros aren't really speedy MFers. They surely have no problems to clear the Pits, but they are slow at that. If you are playing a summon necro for the fun and you are happy about finding useful things every now and then, everything is OK, as that's the true point of the game, but if fun means finding as many nice items as possible, either for using them or for trading or just for hoarding, you should use a different character or visit a different area. Summon necros are good in crowded areas where you can blow up whole screens full of monsters with corpse explosion after your minions have made a few kills.