We loved using the grill on our previous HTT. We used it almost every night and never had a problem. Our wall was fine and the awning never had grey/black smoke damage. We now bring our full sized Weber which is way better but a bigger PITA.
If you do screw the rail into the wall, you'll definitely want to hit at least one stud. On our current TT, I added a rail so we can hang a shelf (made of countertop). I got the stud locations from the TT manufacturer. Another way to find them is to wake up early in the morning when the dew is on the unit. I'm not sure if a stud finder will work. Be sure to fill your holes will caulk before screws.
