Lookin good,
Gamester's right though, you've practically built the shell. Gonna be one heck of a attempt to cut those slots at this point, unless I guess you lay the whole thing on it's side, route, then flip it over.
Rounded corners are the way to go for ease of installation, your gonna end up having to cut notches out for each of those sharp corners to get the T-molding to conform correctly. It is possible but a pain to get it just right without warping the teeth in the T-molding or creating wavy gaps on your edges. Rounded corners just pop in......
For a first cab you work is very nice......Hope to see more.........