Yes you can do it, but your chain line will not be quite as perfect as if you went to a true double. Plus your second chain ring might be a bit larger than if you had a traditional double, so your low gears won't be as low as they might be.
Just out of curiosity, what do you hope to accomplish?
Yeah, you should get a new bottom bracket so the crank will be closer to the centerline of the bike. Maybe 5mm shorter bottom bracket?
If you like this and it keeps you busy, have at it. But saving weight is not a meaningful reason to do this, especially given that you're riding a Sora-equipped bike.
Well, 5mm shorter on the right side. This moves the center between the two chainrings roughly into the position of the earlier middle-ring and lines it up in the middle of the cogs in the rear. However, to preserve even pedal-distance from the bike's centerline, you'll have to shorten the left side as well. So 10mm total. It's typically between 8-12mm depending upon how optimal the original chainline was with the triple.
Due to the angular swing of the FD, you'll need to raise it up about 2-3mm as well.
Use one water bottle instead of two and save big weight.
I see where you're going and we've all been there. Don't spend big bucks (or any bucks), just ditch the granny ring and adjust the FD. Any expense will not gain you anything. Now if you wanted to really do it right you'd need a rear der, new cranks, new BB ..... more than it's worth. Better suggestion, just don't shift into your granny and don't look down (you'll never know you're riding a triple!!!
Whenever anyone posts a "I want to convert my triple to a double" question, several people suggest that it is a useless endeavor. After moving from the mtns to the plains, my triple's smallest chainring was totally useless, so for a total of $260 (I shopped very carefully) I converted to a double -- new crankset, BB, FD, RD. My drivetrain is now marginally lighter, has a slightly better Q-factor, and there is far less chain rub than before, and that's worth the money, to me. So if you want to do it, Equinox, I say go ahead.
I just wanted to have a little fun and feel like an amateur wrench.
That sentence tells me that it would be worth it. You will learn a lot about the bike and pick up some good skills that can be used later. If you can learn to do a lot of work yourself then you will feel that much more pride in your ride.
It may not be cost effective to do it, but learning new skills and having a little fun with it, makes up for that.
That is just the way I look at it.