I carry a pair with me when I travel.
I work with bearings on high speed, high load, proprietary assemblies; we use almost exclusively SKF (occasionally Timken, Lufkin, NSK) and will NOT use a Chinese supplied bearing, no matter how much lower the cost. There are simply too many dimensions to get right and too much cost if a bearing doesn't last. There is a difference in bearing manufacturers.
You mention 6204--the left (disk side of the wheel) rear wheel bearing is a single 6204UU. The flange driven bearings are a pair of 6905RS bearings, mounted side by side, with each bearing's seal positioned to the outside face of the pair of bearings. I mention the bearing numbers only so that a reader of this thread doesn't mix the two.
Regarding the 6905 flange driven bearings: I put Honda-packaged OEM bearings in mine after a set of Honda factory-installed OEM bearings failed at <35,000 miles. (SKF doesn't make 6905 radial ball bearings, or I'd have tried them.) I proactively removed that second OEM set at ~25k miles and they were in good shape (but I tossed them anyway to avoid the temptation to use them longer). I replaced that second set with another Honda OEM set, and that 3rd set is still 'young' and installed.
Regarding the seals, some 6905 bearings are built as "-2RS" and others as "RS" (both sides sealed vs one side sealed). While I believe Honda specifies "RS", folks have used "-2RS" without issue. I think "-2RS" is a bit better (just my opinion). Honda species "RS" with the seals positioned on the outside of each bearing pair (therefore the inner, adjacent faces do not have seals between them)--this allows slighly more space for grease**. The problem is that if one bearing starts to fail and there's no inner seal, debris from within the failing bearing ends up in the still-good bearing--it will fail quicker than if a seal were there to keep the debris out.
**Never fill the entire space within a bearing with grease! Always replace ~1/2 of the bearing airspace with a good wheel bearing grease.
You'll likely hear replies from folks who've successfully used VXB bearings, ceramic bearings, double-wide needle bearings, etc. To each their own.
Specifically to your questions:
1. Honda's part number for their 6905RS bearing is 91052-KZ4-J21. Google it and you can find many places to consider buying it from (or to ask your dealer to get for you).
2. Never use moly disulfide paste within bearings. Such is not proper for bearing ball and raceway cooling and lubrication as paste doesn't have the correct properties--the moly paste becomes hardened moly 'cake', the bearing runs dry (runs hot), and has lumpy moly crumbs spinning inside it! Moly disulfide paste is only for parts with very slow relative motion, high-load surfaces like splines. For grease within a bearing, use a good name brand wheel bearing grease (parts stores have several to choose from).
3. No comment.
3. See #2 above! No moly paste in bearings! Only use moly paste on the splines.
Also, when you put the rear wheel back together, put a very light film of the bearing grease on the axle to avoid corrosion and to allow better heat transfer out of the bearings and collars into the shaft (you want to get heat out of the bearings to make them and the grease last longer).
Hope that helps...
Hey, Just a heads up as SKF does have them. They use part number 61905.....Buy them!