We would still use Mind Blast. It's not as bad as it was in t10, and it's way better than MF and within a few percent of MF:I as far as DPET. The reason why MF:I takes such high priority is its scarcity. When we can use it we need to focus on using it as much as possible. This reduces our normal mind flay filler time as much as possible, which is ultimately our aim: doing anything better than mind flay as much as we can. The same goes for Mind Blast, though. We focus on using it on CD every time. Our damage is actually split up very thoroughly at this point. The majority of our damage doesn't come from one or two spells; we have many significant sources of damage. The balance shifts a bit depending on the type of fight and the talents chosen, but DP and MF:I combined do not make up anywhere close to the majority of our damage. I like the place we're in with the split of our damage among so many of our abilities.
mfi is our best dps spell by FAR. you have to factor in its uptime (18-19% at best) to really get a sense of how much damage comes from it. if you only look at your skada/recount, the mastery proc from MF:I often gets misnamed.
DP is good damage, but really only becomes amazing with UVLS procs and having your haste procs up before you cast it. insanity is great because even if your haste proc goes off in the middle of a DP, you still get significant mileage out of it by squeezing in another 3-4 MF ticks. mindblast is pretty terrible, especially since we stack haste/mastery which do very, very little for mindblast outside of DI (which could use a PVE specific buff, seeing as we're going to have too much haste for PI to be that great next tier). DP also gets dinged a bit from this outside of breakpoints, as the DD of DP doesn't benefit from haste/mastery either.