Yeah, I know you really want that trestle but I'd think about the donut idea for a while. You can make a balloon track around the yard that will serve as your reversing loop. Looks like you could bring it off the existing main just past the right switch of the depot siding. If you bought the left side of the layout down six feet, couldn't you fit in both the trestle and a reverse loop there? You'd end up with almost the same running length of track without the compications of the donut.
The yard changes look fine if you want to stick with the original plan. It looks like you added a team track behind the depot, which is a good idea. The only change I'd make is to have the team track switch come off the connecting track instead of the yard lead track. The less switches on the lead, the better. Even with a small yard, you've alread got seven switches to keep track of and, the more you add, the more times you'll end up with a switch in the wrong position.