three comments:
1) were you done with the welding of the new tongue? I would have expected a bead along the top and bottom, not just along the sides. It would be really bad to have that tongue tear off while you were going down the road.
2) Why no brakes? In some states brakes would be required and they are really a good idea.
3) I am not sure that the rollers are in a good spot or right hieght, but I am not quite visualizing it complete. It looks like the rollers are going to be near the center of the prop guard, and substantially lower. This will put a lot of stress on the center of the guard when the rollers get used. The last thing you want is for the prop gaurd to get bent up into the prop.
My trailer has rollers that are mounted on the vertial supports to the prop guard in such a way that the bottom of the roller is just below the level of the guard. Here, look at this picture:
http://www.dhmtrailers.com/online/home.php?cat=161 This puts any load forces up into the trailer frame instead of creating bending forces in the middle of the guard.