Scaredy - I'm at work, so just a quick response for now...
Yes, I did, at first, have intermittent pain. It wasn't always related to chewing, cold, etc.
In terms of recovery time... For the first 3, I had them done pretty quickly (within a few weeks) of starting to have pain. For those, I was pain free immediately after (a little sore from the injections, but no tooth pain at all). For the most recent one, I waited a couple of months and it took a few weeks to fully recover, though I was able to eat without a lot of pain after a day or 2.
It usually does take about 90 mins for a molar, but there are lots of times to take breaks to close your mouth. The rubber dam will keep all of the stuff out of your throat, but won't keep you from being able to close your mouth. The dentist will switch tools a lot so when s/he does this you will get breaks. You can also ask for extra breaks if you need them.
Let me know if you have more questions and I can write more later.