I prefer to keep some of my currency liquid. More or less for the reasons that you have stated. But I also convert my Hive to other coins, mostly LTC.

I like to have a mixture of crypto, and have at times needed to convert my crypto to Fiat. Such as a short while ago when I needed to pay off my wife's credit card, which I did with my remaining Steem.

So it makes sense to power up what you can afford to power up. But also keep some liquid for use or trading as you see fit.