Balancing an economy is not simple. The Hive one is pretty small right now, but if it got huge then it could make things trickier. I just read a post by @demotruk on circular HBD economies, so you seem to be thinking about similar things.
I've not got a lot of HBD savings as I find HP more interesting, but it's good to have these options.
I agree, it definitely gets harder as things get bigger
That being said, I think Dalz has done a great job of outlining that it's not going to suddenly get HUGE overnight... it takes buying HIVE and converting it (burning it in the process) to print a bunch of HBD
That would make the HIVE price balloon like crazy, enriching all HIVE POWER holders
The balancing act that HIVE-HBD ecosystem has between HIVE POWER, HBD savings, conversions and generally low liquidity is quite fascinating
It prevents us from growing super large in a short period of time which is both a hinderance and a protection