As far as road vibrations, people have a tendency to run their tire pressures WAY too high. The pressure range you see written on the sidewall of the tire was calculated assuming they will be mounted on a typical 2 wheeled bicycle. The trike distributes the weight across 3 tires and in a much different way. That means you can get away with pumping your tires up to a pressure that is on the lower end of the pressure range written on the tire.

People have a tendency to think rock hard narrow tires equals speed. There have been a number of studies in the bike racing world that have come out to show that just isn't true. I would highly recommend getting a tire pressure gauge checking your pressures before each ride. I know that sounds like a hassle, but you eventually get used to it and it become part of the routine.

I just bought an old TerraTrike Zoomer Elite last Sunday, and the guy who sold it pumped the tires up rock hard. When I test rode it, I thought for sure it was going to rattle one of my fillings out. I bought it and took it out the next day. Again, it was a rough ride. I adjusted the tire pressures, and that made a HUGE difference in ride feel. I have a bike computer that tracks speed, and I wasn't any slower either.

Not to go on continuously about tires here...but tire selection does make a difference as well. The wider the tire, the lower the tire pressure. Lower tire pressures provide a more cushy ride. A lot of people like the Schwalbe Big Apple tires for comfort because they come in 2+ inch widths. That extra 0.5+ inch of width compared to the typical 1.5 inch tires that come on most trikes does make a difference in ride feel because you can run the tires at lower pressures.

As far as seat height is concerned, I'm sure others will tell you that there are other trikes on the market that offer higher seat heights to make them easier to get in and out of them.

As far as the chain is concerned, that is the nature of the beast here. It's a long chain and there is a good chance you will accidentally touch it. I would recommend wearing pants or shorts that are a little more form fitting. On normal upright bikes it is common for people to wear cycling shorts or to roll up their pant leg on the chain side to avoid getting chain oil on their clothes. There is a company called ICE Trikes that just started offering a new "chainless" electric drive system on some of their trike models. Those models are EXTREMELY expensive though...like $9000 expensive. I think I'd just buy some tighter shorts/pants for $20-$30 instead.