Should I be worried about an RV that is too long?

I've towed many trailers and many different lengths. As stated practice makes perfect. I like to do the spotting myself, even if it means getting out several tomes to check. Just remember your longer and you should exaggerate your right turns. Having a good set of mirrors is important to see the trailer as it turns corners. Empty parking lots work great. Set up some markers and practice. I would not buy because of too long or too short, I would buy what is going to work for you and yours.