I won't comment on the PSE stuff because I have no knowledge of it.
If that suppressor is vibrating loose, I'd go get some of the non permanent loc-tite and apply to the screws on it. This will keep them snug.
As for the best strings. There are plenty of really good makers out there these days. Vaportrail is my personal favorite and have been shooting them for some time now. Winners Choice is another popular string maker. They're both on the pricey side, but the quality and performance is second to none.
As with anything, you get what you pay for.
Spot Hogg Archery
Lone Wolf Treestands
Slick Trick Broadheads