My daughter has CMTC and not a PWS but I can relate to your hotel story. When we were at a hotel we were trying to get Becca used to the water temp. These people kept staring at her. Then when we put her in the water the lady got out-how rude! Anyway your skin will get thicker! I used to cover Becca up all the time but with shorts and the summer I have realized people are going to see her markings. I actually heard people talking about how Beeca got hurt and what caused it. I stopped the people in their tracks. She was not hurt or beaten but has a condition called CMTC. They were embarrassed by their actions. I know of families who actually carry cards explaining CMTC for this reason.
As far as treatment I don't know a lot about laser because it isn't effective on CMTC. Hopefully more parents will be around soon. Best of luck!