Yogscast videos are terrible, and not even worthy of lulz.
And dropping Improved Mind Blast because Mind Spike makes it Instant? Have you even looked at the tree since vanilla?
Improved Mind Blast is not a cast time reduction, it's a cooldown reduction. As of 3.1-3.2, it's also an "MS" effect.
The fact you'd even recommend dropping the MS effect "because it's instant" makes me wonder where the hell you've got your info from?
Or was there more terrible garbage from yogscast that we're missing?