Its fun isn't it!

There's nothing wrong with straight gauge. You don't have to think of it as cheaping out either, you're gaining an advantage in durability and in reality the weight savings can be more than offset by using a quality tire. The strongest wheels I've built are on my Schwinn Varsity. They're 26" Rhyno Lite rims and straight gauge spokes and these wheels take a pounding and never flinch.

If you've got a wheel that's tensioned and true I think you are correct, shouldn't need to worry much as long as you use good rim tape. You could always trim the spoke ends if you were really concerned.

if you are using spokecalc, consider a different calculator. I think you'll find that there's more folks than care to admit who've had spoke lengths come up wrong and I'm of the opinion that its spokecalc to blame. Google spoke calculator and use like anything else. I like this one and have had good results with it http://www.prowheelbuilder.com/spokelengthcalculator/

as for tension i just shoot for 100-120 and settle on whatever the wheel seems to want.

I'm no professional. I've got just shy of a dozen sets under my belt at this point, but I am feeling more confident lately.