Nothing to worry about at all.
If you're buying used, make sure the bore is spotless. Then, in either new or used before you shoot it, DynaBoreCoat the bore. You will thank yourself later, every time you shoot it.
The Rem 700 is just an odd duck. Why go with a bolt action on a muzzleloader? You're adding weight and length when neither is needed or desirable. I have no experience with or around the BPI. The CVA is a decent ML, but be wary of the years and SNs involved in recalls. If it's outside of that, use it sensibly. The Knight is a good, solid, older ML.
America needs to understand that our troops are not 'disposable'. Each represents a family; Fathers, Mothers, Sons, Daughters, Cousins, Uncles, Aunts... Our Citizens are our most valuable treasure; we waste far too many.
