There are many dual purpose hops that can be used for bittering and dry hopping. I have an old chart that I found in Brew Your Own that I use for reference. I'm sure you could Google hop characteristics and find many that you can use for bittering and aroma.
We should get together and brew sometime. Benson is close to where I live (Garner). I've been brewing for a long time in years, but typically only do one or two batches a year. Sounds like you're already more advanced than me on the post-brew equipment side.
It's probably not ruined, but I've heard if you dry hop for too long it can give the beer a "stemmy" taste. Some people dry hop for as little as three days. I like to dry hop mine from 5 - 7 days.
I don't always take a gravity reading because the ABV "is what it is." However, it can be useful in letting you know that the beer is finished fermenting.
I've done a few DIPAs and I used about 98% 2 row pale malt and I've even made one batch with 100%. I like to keep the grain bill simple. For a DIPA, I use about 3 oz of bittering hops - one at first boil (usually the most bitter one - Magnum, etc.) and the other two around :30. The I dry hop the...
I sometimes fantasize about opening a brewery that sells baked goods - a beerkery. I make awesome carrot cakes, pond cakes, zucchini bread, etc. My beer's pretty good too.
I usually do move my beer to a secondary prior to dry hopping, but after reading a few comments here, I decided to dry hop in my primary on my current batch.
Don't know exactly. I didn't add anything to cool it down - just opened the lid and stirred a lot. It wasn't a constant 168; it was gradually lowering to the target 155. That process took an hour.
It tasted good, but I'd never be able to duplicate it again if I wanted to.