Did your RV manufacturer supply a water pressure regulator? No.... :B
I'm going to give an opinion based on actual experience using slide stabilizers, not guessing. They work great if used properly. I have had a flat tire while the slide was supported with a stabilizer. Not a problem because the trailer frame was properly supported.
I use the stabilizers when my grown boys come to stay. A lot of weight and horsing around added to the slide out. I also use them on long stays on firm groun.
Opp.. I doubt the new couch warrants stabilizers but if you decided to use some, just make sure your trailer frame is properly supported and don't put to much pressure on the slide stabilizers. Use them to support..
As with most everything else, if used improperly they could cause damage.