I'm pretty far removed from OCS at this point, so I don't know what the newest list of display items is for RLP.
Having said that, when I attended I brought a lot of items based on gouge to leave in POV for later (eg starch, goo gone, etc), and discovered that there are entire rooms filled with pass-downs of this stuff from previous classes. If you really, really need something that's not on the official to bring list, the candios can make it happen for you via another run to the uniform shop or king hall mini-nex. If your PT gear gets stained and you can't do anything about it, you can go to the uniform shop and get another pair. Also, from what I hear some of the class instructors really cracked down on POV runs in the early stages of training, so if you get unlucky the unauthorized stuff will sit there until after RLP, which is what you would use it for.
The candios are likely to limit your initial belongings to strictly what is on the official OCS website "what to bring" list, so walking in there with all that stuff on day 1 will just be pissing money down the toilet.
Specific things on the list that are unnecessary:
-Binder clips: wtf you need those for?
-Black sharpee: you will purchase a pack of two in your first uniform/item run.
-Black boot socks: You'll buy your own from the uniform shop. Bringing your own is not a bad idea if you have bad feet or are picky, but you'll need more than two pair of boot socks as you wear and sweat profusely in NWUs everyday.
-febreeze/googone/hair spray/staflo/superglue: don't bother. There will be plenty of that stuff around.
-Headlamp: Generally no need for it. Never saw a DI after 18-1900 ish. Had one and never used it.
-PT shorts and shirt: No need. You get issued two sets of PT gear, including long sleeves and sweats. You can use both and still be fine for RLP. Also, the PT gear at OCS used to actually say "NAVY OCS" on it, so you couldn't even use normal fleet PT gear for wear or inspections. Dunno if that's changed.
Note: Get the sweats a size big because the DIs love to make you put on/take off PT sweatpants with your shoes still on as a timed evolution.
-Inspection sneakers: bringin a spare pair of running shoes to switch out is okay. Buying a pair of sneakers just to display for RLP is silly.
-Nail clippers x2: Do you have an issue with nail clippers breaking or something? One set is enough.
-shirt stays: issued at uniform issue.
-crew neck t-shirts:issued at uniform issue. The white ones were really crappy, but now that NWUs is the main thing until candio, it doesn't matter.
-stationary: you are issued navy stationary at your uniform issue.
-body/hairwash combo: space is not really all that much of an issue at OCS. I never felt like I had to cram a lot of stuff all over the place. The extra space a 4" bar of soap will take up is not really all that significant.