The answer to most of your questions is we are all different.Higher voltage or lower resitance heats the liquid hotter quicker so you get more warmer vapor.It usually does change the flavor ,some liquids change for the better some not so much.If you are just starting out I would suggest you stick to the basics.Get an Ego type battery ,there are lots of good deals on EGO tank types.The tanks don't work as good as other options but do work and you can ditch them when they go bad.You are mostly after batteries and charger.The you have to experiment with stuff like Boge refillable cartomisers,dripping with Ego,Joye 510 and 306 atomisers and Vivi Nova Clearomiser or Vision Clearomisers.Any of those should do a good job ,the tricky part is finding liquids you like and for that you just have to try a little from everybody until you find what you like.Hope that helps.Kind of overwhelming at first.