Re: I broke my cherry!
If you're going to decelerate or coast, pull the clutch. Engine braking with a two stroke is bad.
Choke: lever up to start, lever down as soon as you can.
Full throttle? To me, no problem. Ride it like you mean it.
No tensioner? As long as the chain has about a half or three quarters inch play when you're standing still and it doesn't jump off, this is good.
Let the clutch handle out gently, so as not to wear the clutch pads too quickly. Pull the clutch handle as fast as you like.
Back yard over the winter: put a cover on it, and expect it to start harder in the cold. Check your tires very regularly. Check tightness of nuts frequently, as the wide hot/cold cycling will tend to loosen things. Don't overtighten; a torque wrench is a good idea.
First problem: dirty air cleaners element. Squeeze the fuel out if it occasionally. The magnetos tend toward failure, too, but that's not a certainty.
Mean time to failure? I don't know the answer to that. I only have one, and the engine has been fine for 500 miles.
Unless something fails, you should never have to take the engine apart. You may need to clean the carb occasionally, with disassembly of it.