The airlock isn't a gauge of fermentation. Yes, sometimes, even often, it appears that way, but it isn't. If you pitched enough healthy yeast it will be fine. Check gravity a bit down the road.
Yes, but after the conversion happens at 148 for the hour, not much else is happening at the hour 154 mash. Maybe a bit more conversion. That said, I really don't think there is any harm done. Lots of folks mash IPAs at 148 to make them drier and less sweet.
I honestly bet its fine. Two yeast packets fine with that OG. You will get your system down in future so you can mash at the temp you prefer. Tough to gauge when conversion happened, but possibly at a higher temp than you wanted. In which case it may not get to the FG that you wanted. Then...
Just be careful. Running multiple protection programs at once can create problems and be counterproductive. If you google "computer protection Lifehacker" some helpful articles come up on that site.
Big fan of this session IPA I brewed. Split the batch, dryhopped half with 4oz Galaxy, half with 2oz Simcoe/2oz Mosaic. Latter is much better. Next time might do 2.5 Simcoe/1.5 Mosaic and either Pearl or MO as the base, or more Munich.
Recipe: Session IPA
Style: Standard/Ordinary Bitter
TYPE...