Well first all these numbers including the total supply can be changed with hard forks if there is enough shareholder approval. But let's consider what is possible without hard forks. Also, let's assume another change to increase total supply above 3.7 billion BTS is so undesirable that we would "never" hard fork to do it. If the rate at which BTS is pulled from the reserve pool follows the same hard-coded rules of the current BitShares system (5 BTS/sec and halving every 4 years), then there is effectively no difference from a dilution standpoint. However, if a majority of the delegates are able to change this number, then that is a different system than what we currently have. Dynamically adjusting the number makes it much easier for a large enough quorum of stakeholders to effectively retroactively reclaim funds that we earlier "burned" (but still never exceeding the 3.7 billion BTS hard limit, assuming no hard fork). But I don't think that is necessarily a bad thing. I would like clarification on whether the rate that is pulled from the reserve pool is set by delegates or hard coded (or maybe it is set by delegates but with a hard-coded upper limit?).
Regarding the bond market, I have some other concerns actually, but I rather just wait until more information is provided. Personally, I consider it a work-in-progress that will likely be greatly improved over time. I'm just glad that it is being considered a priority though.
Regarding the high transaction fees, I believe different operations can have different fees set by the delegates (is that correct?). If so, my concerns about the fees is greatly reduced. I think that certain operations like updating an account's votes and placing and cancelling limit orders should have very low fees (in fact, I think we could just get away with making cancelling orders free without worrying about spam issues). We shouldn't penalize people who update their votes because they help keep the system secure and running properly. And high fees on placing and cancelling limit orders hurts bots which will hurt market makers and thus liquidity. I would rather have very low fixed fees on placing market orders and have percentage fees on the matched volume instead (but still at a lower rate than our centralized exchange competitors). But I am fine with all other operations (including transferring assets from one account to another) having the higher fixed fees for the sake of the referral system.