how important is it to have your oil line perfectly vertical? i mean i have mine set at about a 15 degree angle so the oil will drain better into the pan. is this ok?

 

Fine. Ultimately there are few oil drain lines out there that don't make at least a total of 90° turn. As long as the drain line does not come back upwards, as long as it is of adequate ID, and as long as the point it enters the pan is above the oil line, (and as long as the feed line is good to go) you will be fine.