i think this post only got one reply because most ppl in this forum, myself included, would say exactly what fueler already said about the battery. take it in and have it tested first, the battery itself is more suspect to causing an issue that something draining it at that high of a speed, unless theres tons of stuff plugged into the 12v aux jacks. unfortunately the faulty sensors are an all too common issue with the 3.5. as far as the rough engine, could be because the battery isnt holding enough juice to give a good spark, among other things. start by getting the battery tested at a parts store and replaced if it proves to be bad. then see if the rough idle is still there. as far as common issues, heres a link that pretty much sums up the pathfinder/qx4
zerothread/214837