I believe the inflation of the currency takes place over the next 40 years so I am not sure it is really a major problem for a while.
As for diminishing reward pool, I think the idea is the increase in value of STEEM more than compensates for it.
Which makes sense...a .9.5% inflation rate should easily be outpaced...if STEEM only increases at 10% a year, that is poor in the crypto world.