You may not want to, but you'll end up using a little trim here and there depending on a great many things. Adjusting the trim isn't an every flight task, but I'd guess that I make a small adjustment here or there in most of my flying sessions. It becomes second nature, and you don't really think about it much.

Yes, you should try to get the mechanical linkages set up so that your transmitter trims are centered. Turn on the TX and RX, and make good note of where the surface is. Center the trim, and make the adjustment necessary to bring the surface to the position it was in before you centered the trim. Do that one channel at a time. One of the reasons for doing this is that you'll have the full trim travel available during future flights. Nobody likes to run out of trim--it makes for unhappy flying.

Computer radios have made many of us pretty complacent when it comes to our mechanical linkages. Dialing the trim out with sub-trim on the radio is a bad habit of mine. I tell myself that I'll do it the right way when I get home, but... It's just better if you teach yourself the good habits at the beginning. It's pretty rare to regret doing things in the right way.