I'm not quite doing what you're considering as there's hills around here. But I went with a single 36T ring and a bashguard for my light duty trail and local market errand ride. It's got 8 speeds out back which is more than enough.
If you're living in a really flat area a 44 or 46 would be a nice road bike single ring and it's perfectly doable. But to help center the ring you'll want to move it to the inside or center position so it lines up wiht the middle of the cassette. That will avoid any issues with cross chaining. And from my roughly 7'ish years of riding my single front gear bike you can forget about the need to keep the FD as a chain guide. I can't remember a time when the chain jumped ship. Although the bash guard MAY have kicked it back into place here and there. But it's never jumped off the inside either. Or if it has the time was so long ago and so infrequent that it's lost in the dust of my mind. When I first did this I was worried that the tooth profiles and ramps would encourage the chain to jump. But it never did. What DID happen due to the tooth profile was that the ring wore out fairly quickly for the amount that I rode it. The replacement was a slightly cheaper non ramped Black Spire ring that has full profile teeth. That ring has been going strong for about 5 years now with little or no sign of wear. So keep that in mind for later.