1. click on your gusset with right mouse button and select Edit Definition
2. click on gusset options
3. in gusset options select Include Rounding
4. enter appropriate values for Punch and Die radius.
I looked into your part.
Why do you first draw a sketch before the cutout?
I also see you have 4 times a mirror. You can do all this at once.
You start with a contour flange, that's perfect, but further you use a contour flange of a sketch again. There you can use a "Flange".
Also I see you have a lot "under-constrained" features.
It is not required to fully constrain all, but I don't continue without.
For me, Synchronous is great for the beggining of the project. But when I come to the detailing, I go to ordered and finish the model with all the detailes. And sinceST3 I think, switching between two technologies is possible in the same model.
1. start to model in synchronous
2. then, place the coursor over the Synchronous node in Pathfinder. Click with right mouse button.
3. now, select Transition to oredered
4. finish your model with all the details (sweeps, lofts, face blends, etc.) in the ordered environment.
Great think here is the changing of the model. Even though you are in ordered environment, you dont' have to switch back to sync, to make a simple change. SE will know, that some features are from sync, so they will be also changed like this.
To see this in action, see the attached movie.
I know you are new to Solid Edge, that's why I thought to help a bit, not to nag.
In synch I can't help you, I am a dynosaur who can't get used to it. With ordered I can help you if you like.
Other than in synch in ordered you can draw the sketch and make the cutout in one feature. So don't draw the sketch, close and make the cutout.