Yes, I do believe caffeine raises blood sugar.
I don't have anything on caffiene, but have had experience with the "alcohol phenomena". I always found it reacted strange in my system, and I may wake up the next morning with lower than normal sugars, but it's not a good bet and is dangerous. The way I had it explained to me is this: Your body considers alcohol a foreign substance and will drop everything to process it out of your body. All absorption of carbs stops until the alcohol is out of your system. Now, if you think, this is very, very risky. If your sugars are normal to low when you start, you risk a hypoglycemic reaction that you can't treat, and even worse, your alcohol intake/effects may mask low sugar symptoms. A very dangerous combination and I would NOT recomend using alcohol as a lowerer at all!!.