Yep, so the concept of Resource Credits was born to quantify and put limits on resource usage. It sounds like you are dealing with all the same problems of the base layer. And these problems were solved well on the base layer (Hive), or at least it seems like that to me, but I don't know if you see it the same way.

Delegating Resource Credits also seems another quite useful feature that's coming which I imagine could be useful also to the second layer if it utilizes something like RCs.

Regarding utility, don't you have that problem anyways? If you pay BPs with crypto, whether directly or through inflation, the token you pay them with has to be worth something.

Regarding speculation - if the price of Hive goes up, does the cost of transactions go up? I am not sure. Maybe you have more insight. The cost of transactions is quantified by Resource Credits and it stays the same regardless of Hive price. But you accumulate RCs if you stake Hive, so there is an indirect connection between Hive price and RCs/transactions. But we've seen Hive (well, Steem) prices of $6-$7 and it didn't create any problems with transactions becoming expensive. Maybe for newcomers who have to stake it is more expensive, but it is a one-time expense to stake the tokens and then your RCs get continuously replenished. So that's a fundamental difference between the RCs model and models where you pay for transactions with a token that can be speculated on.