My take is that there are a lot of things you CAN do. The question is whether you really want to.
The cheapest approach would be simply taking off the inner chainring and adjusting your limit screws so the derailleur doesn't toss your chain onto the BB shell. You MIGHT think about getting one of those 'chain keepers' that prevent that, too. It's cheap insurance, because you'll be shifting to the small ring when you hit hills and if you drop your chain then, after you put it back on, you'll be starting out uphill.
One advantage of a double over a triple, however, is reduced Q factor. That is the width between the pedals. I find I'm sensitive to that, so in rebuilding my 1995 Cannondale from a triple to a double, I'm replacing the crankset and BB with an actual double and a bottom bracket with the recommended spindle length, which will move my pedals closer together. On other bikes, I've always used a BB with the recommended spindle length, to maintain chain line and Q factor.
But that's me. I'm building the Cannondale as a vintage bike, with downtube shifters and all that, so it's part of the aesthetic to get it 'right', rather than just what will work. It's a project, and it won't be my main bike. More like something for noodling around on sunny days, not doing big climbs or epic rides on.