I am building a 1x9 with an old crankset I have lying around and have a question about how the chainline will turn out. Since I will be using the 44t ring on the outside, and this crank came with a 68x113 BB, wouldn't using a 68x107 BB keep the chain centered better on the cassette? I can't think of any reason why this would be an issue. I know I could move the ring to the inside, but the crank would not look as good, and using a shorter spindle will make my cranks closer together. If I bought a new single speed crank, I'd have the same result anyway.

Should work fine.

If it were me, I'd run the 44T in the middle position and install a bashguard on the outside. It'd look good and be pretty cheap. https://www.bbgbashguard.com/Mountainbike.html

Whatever you do, make sure it will clear the chainstay.

It might improve the chain-line, but you need to also make sure you have the chainstay clearance to move a 44t chainring in that far. Most frames are configured to clear 39t and 42t chainrings in the inner position, but the right stay comes out at an angle, or is only crimped so far, so as you go to larger chainrings you need to move tham out more. 44t isn't that much more than 42t, but it's still something to consider.

Good advice - I had not considered that. I'll check it out. Liking the look of some of those bash guards. It would add a nice and unique touch to the new build.