As stated above, you will have to do a partial mash in order to get all the oat goodness. The good news is that it is very easy; I followed DeathBrewer's tutorial with this recipe and it turned out wonderful. If you don't want a big coffee flavor, just skip the addition in the secondary...
This sounds like a neat idea; I have a 6 gallon batch of lemonade going right now, and am seriously contemplating adding some crushed caffeine tablets to some of it in order to replicate what you are doing.
The best advice I can say about making hard lemonade is to actually use the lemon must...
Back in my younger days, I used to purchase brewing supplies all the time, and never had to give ID. Consider that nothing you are buying is explicitly illegal for minors to have, so long as you don't do something silly and try to turn it into an alcoholic beverage.
If you are really...
I'm surprised no one has suggest using an Old Rasputin from North Coast Brewing. I tried this over the summer, and the vanilla does an excellent job of mellowing some of the more powerful flavors.