2 gallons is just fine, I just finished a 3 gallon batch of dunkelweizen a little while ago. If you're using a 3 gallon carboy, go ahead and bump up your volume to 3 gal going into the fermentor. There should be enough room for it in there as well as your krauzen (use blowoff if needed). That way, after the yeast and trub settle, you'll end up with closer to 2.5 gallons in bottles. If you start with 2 gallons going in, you'll probably only end up with a little more than 1.5 gal at the end of fermentation.
Otherwise everything else looks pretty good. Personally I'd go with a slightly higher mash temp, probably in the 152 153 area for a little more body. Your cane sugar should take care of your abv, but if you mash too low you'll lose body and it might come out too thin and dry. Since it's only a small batch however, give it a go and see what happens. My best learned lessons were from my brewing, not from forums