Will the decreasing Bitcoin production cause a liquidity crisis? Based on the fact that the bitcoin "production" will stop around 21 million bitcoins, could this lead to a bitcoin flow freeze? 

What I mean is, if we produce all 21 million bitcoins, and keep using them nicely (without inflation issues because there will be no more making of them) wouldn't some pals need more bitcoins than others? And a lot of users wouldn't want to use them through stores, debit cards and/or gift cards? Then how will the currency recycle?
Bitcoin's reward rate isn't constant - it halves every 4 years, and eventually stops entirely in 2140.

https://en.bitcoin.it/wiki/File:Controlled_supply-supply_over_block_height.png



See also: The End of Mining