Even on the PK the habaki is functional. Otherwise there'd be nothing holding the sword into the saya when sheathed. The problem with the old plastic habaki on that line was that they'd crack when used properly.
Either way, a loose habaki = pretty much nonfunctional sword. At least for JSA stuff. A few rather accomplished swordsmiths have long felt that the habaki itself is a mistake, preferring a western-style ricasso instead. Just because so much rides on the habaki being perfectly matched to the blade. Tsuka fit and longevity, overall tightness of the mounts, and of course the seating of the blade in the saya. In fact, it might actually be that the habaki sits tight in the saya, and your blade is rattling around in the habaki itself. Not good at all.
As to the saya fit, keep in mind that most sword factories pre-carve their saya. Once the blade is made and fitted, a saya is found that best ("best" depending on what's available and the diligence of the workers involved) fits the sword. So no, you won't come close to the fit of a custom-made piece.
Since the Cold Steel series is billed as a functional piece, I'd say you've got more than enough grounds for an exchange or return. A loose saya can be repaired with shims, but a habaki should not be. Tsukas and sayas are consumables, but the habaki is basically a part of the blade itself.