Timebanks... is this similar to things such as the LETS system? Or possibly bitcoin-denominated Ripple?

Personally, that's kind of what I envisioned. Once material goods are truly abundant, the most valuable things will become human services/performances and new ideas. The only way to keep track of those things is a simple accounting setup of some sort... possibly Bitcoin-like. So this makes sense.

I don't think there will be enough people gifting massages (at least, excluding creepy, over-eager masseurs no one wants to go to) to meet the demand of people wanting them though; I could see timebanks hanging around just to deal with this sort of excess demand. We'll probably have to agree to disagree over whether machine massages would be more desirable than human contact.

Now, here's where I kinda get to my point. If timebanks are around, and I'm incentivized by them, likely others would be as well. This essentially would turn timebank credits into a form of money, and even if it's small, some sort of market (complete with exchange rates, etc.) would likely develop around it. ("Oh, honey! Five timebank credits! What a great birthday present!")

And, humans being human, a certain level of status or prestige would also likely become associated with accumulated credits. ("Man, that guy has a million credits! He could provide some pretty sweet services for himself and his kids for decades!") And of course, gifting credits or transferring them to ones descendants would be possible unless there was some deliberate attempt to prevent it (which, like today, would be worked around.)

If this market is allowed to function, even if socially frowned upon, then I guess that's the end of my questions. Essentially, money could crop up in a RBE, and those wanting to make use of it wouldn't be stopped from doing so. In which case, provided getting to this ideal is completely voluntary, I don't think I have any issues with RBEs.