Tough brew day--1st pm

So I tried a small PM yesterday while brewing my first IIPA(hopville . "OTO IPA" Imperial IPA Recipe). I did a variation of Death Brewers stovetop process. Turns out I mashed my 2lbs of munich for 30 minutes at 160. Once I realized it I was able to bring the temp down between 150 and 155 for another 30 minutes. Also, my sparge temp was a little high(180). So, I'm guessing my efficiency is way off. I was shooting for an OG of 1.078, but it came in around 1.070. Does this account for the miss in OG? I assume it means I didn't convert enough fermentable sugars from the grain. I'm just curious how this will effect my beer? Any other comments and suggestions are always welcome. Again, thanks in advance for all the help.

p.s. It was going nuts in the primary after 12 hours.

This will probably be very malty, given the combination of Munich and high mash temperature. 160F is at the limit for alpha amylase and the betas were completely wiped out. I doubt you'll be disappointed though.

Update and new questions.

So on top of bad brew day temps, our primary fermentation got a little out of control as well(79 deg before we could get it in a swamp cooler). However, the gravity has dropped from 1.070 to 1.013. We're going to check it again in a day or two and if constant, transfer to secondary. Then dry hop for 7-10 days.

We tasted the sample yesterday and it was pretty bitter and a little twangy/astringent. You could def. taste the alcohol. I assume this is a combination of being over 7% and from high fermentation temps. I've heard this will subside with time, but what is an ideal mix between letting it smooth out and not losing the hoppy freshness? Should we secondary for a week or two before dry hopping, or maybe longer bottle condition?

Thanks again in advance for any more comments or suggestions.