I agree totally with the above, a well made Marzen is a thing of beauty. I am also not a fan of upping ABV for it's own sake... if a higher ABV is the natural outcome of a particular beer (doppelbock for instance), great... however, there is something to be said for "session beers", I want to be able to enjoy a few without having to worry about being useless for the rest of the day!
All that being said, the beginner's mindset (I do not mean that in anyway disparaging!) is a great thing as well. Too many times experienced brewers get hung up and perfecting some process, nailing every parameter of a particular style, etc. The wonderment of brewing without boundaries can get lost. If you want to do something wacky, check out some of Papazian's recipes, Goat Scrotum Ale is a great jumping off point for that sort of thing.