RR+ Items

[thorny moat]

If you buy rr+ items, but then stop paying for rr+, are those items still wearable without rr+?

[jolly verge]

i believe so

[ebon crest]

Yes. They say "Rec Room Plus Items" because you need RR+ to purchase them.
Once you own them, you can wear them whenever. This is the same for the monthly items (the most recent one being the oceanic mkp). You don't need rr+ to use them, just to obtain them.