If you do plan on using pyromancy, get your Flame to +10 and talk to Quelana before killing Bed of Chaos. She sells some of the best pyromancies, and is the only vendor that can ascend your Flame.
In case you don't know, casting speed caps at 45 DEX.
If you do get some powerful pyromancy, there's an amazing soul farming spot in the Painted World of Ariamis. Roughly 8k souls every 30 seconds.
NG+ is a pretty big spike in difficulty, but it doesn't get easier for NG++ onwards, it's just the difficulty increases are much smaller than the one from NG to NG+.