An American wheat should generally be finished fermenting in about a week or two, then another couple weeks to carbonate. You'll be drinking this within a month.
You can add a pound of cane sugar just as well as corn sugar. Cane sugar works great, and much cheaper and easy to find in your kitchen cabinet. Either way, but you might as well save a couple bucks.
Easiest way to figure out alcohol is to look at your original gravity. OG=1.043? Your alcohol by volume is roughly going to be 4.3%. With an extra pound of sugar, your original gravity might end up closer to 1.052, so that's about 5.2%. Rough estimate.
The real way to calculate it is the difference between original and final gravity, times 130. So, for OG=1.052 and FG=1.013, that's (1.052-1.013) x 130 = 5.1%. Not entirely accurate, but good enough within 0.1-0.2%.
By the way... ferment cool in the mid-60s if you can. Will turn out better than if fermented in the 70s. This goes for ALL ales.
Best of luck to you.
"This is grain, which any fool can eat, but for which the Lord intended a more divine means of consumption. Let us give praise to our Maker, and glory to His bounty, by learning about... BEER!" - Friar Tuck (Robin Hood - Prince of Thieves)