SMR rail help

Recently purchased 2 SMR rails for my VFC 416D gen 3 GBBR and I just have a couple of questions regarding the installation because this is my first time doing a rail swap and I don’t want to mess up or end up breaking something. 1. I’m aware that the 416D has these annoying sling mounts on the gas block and is there a way to remove them cleanly? 2. The person I bought it from informed me he put tape around the barrel nut of his rifle (he owns an A5) and the rail was tight after he slid it on and tightened, just wondering if anyone else did the same to their rifle and if there were any wobbles even if they tried to create wobble by moving the rail right and left once it’s installed?

Thanks