It's true that SPS won't be needed to play Splinterlands, the idea is to have everything cool withing the game require you to either have SPS staked or pay a premium to someone that has. I do like the concept but we'll have to see how things play out in the end.
Regarding the inflation rate - it's a problem short turn, especially because of the VCs just dumping what they get, but on the other hand the total print will be 3B and that's known already so people can plan accordingly. I'm not stacking SPS to sell it again anyway, so I'm not too much worried about it's short term value. Things should improve a lot once the airdrops end.