I used them for years. Replace the tuping every season and no problems. No rotating peep from string stretching.They are probably the worst peep available in my opinion for several reasons. And no disrespect intended here at all, but I'd have that removed and reinstalled at an archery shop.
Yup, too loose. You need a few more wraps of serving on there to tighten it up.
And change that rubber often, with new tubing. If that snaps, it's going right in your eye. Ask me how I know...
Anything on the string slows the string down! The tubing is also notorious for breaking and whacking people in the eye. To each their own, if you like it keep it! But most professional shops will not encourage using them as the others have mentioned. A properly installed peep will not move!
And string stretch shouldn't cause a peep to turn either...