Well, it sounds as if your base idle is tad low. Probably around the 500rpm range. It usually doesn't show until later in mileage, around what you have now. Most places won't check or set the base idle/timing during a tune-up. You really have to request it.

A tune up will never hurt. The only thing about doing it early is that you won't really feel the full benefit (like having a poorly running vehicle, then all of a sudden, runs like new). That's not really a problem, but don't expect to feel major results.

I'd reccomend having the base idle and base timing checked. If your new X was babied, then perhaps an intake cleaning may do some good. Carbon (from Grandma driving slow in the left lane while on the way to Church on Sunday) may have deposited on the valves, causing some minor idle instability.

As far as your mirror, yes, the light indicates it's on.

Try this. During the day, sit in your X with the key on (so the light in the mirror is also on) and feel around the back of the mirror with your finger. You'll feel a little divot. Cover the divot with a finger, and watch the mirror. It might take a little bit (maybe 10-15 seconds), but the mirror should dim (turn greenish-blue). That's about it for the mirror. Light on, auto dim on. Light off, no worky.