yes, mindblasting on cooldown is what you want to be doing. the only thing i would ever delay a mindblast for on horridon would be a SWD snipe on an add - and that's just for 1 gcd and only b/c that opportunity to get that SWD orb may not come again that DP cycle.
also, remember that in world of logs you can hit your name, then buffs cast and hit the # link to see when/how you are using your cooldowns, pots, and DP/insanity.
so much of our damage comes from DP/insanity burns that you always want to use your CDs for this. it doesn't look that way in your skada, but you have to factor in that you're getting only 20%ish uptime on your DP/insanity.