IMO, face frames do not look good or right on furniture. They are for cabinets. I define face frames as wider than the thickness of the board they are being attached. So, if you have 3/4" plywood sides, I would say 1" would be a faceframe, although 1" I think that would probably be OK.
As for strips, you could rip some 1/4" or 1/8" strips 3/4 wide and glue them to the front edges of the plywood. For that matter, you could rip them 3/4" and they would come out flush to your base, personal preference and whatever you want to design works. Basically, you are making your own strips, but a bit thicker and attaching with yellow glue and clamps. Once you get them on, you can use a sharp block plane, a sander (have to be careful not to sand through the veneer on the plywood DAMHIKT), or I have seen a jig with a router and flush trim bit made to even it up. I am not sure if your carcass is already glued together or not, but if it is, it makes a little more difficult, but not unrealistic to do. If it isn't glued up, it is a simpler matter to glue on the strips, rig up a router in a table with a high fence and flush trim bit, and even them up.
As for attaching the strips, yellow glue holds a lot better than the iron on strips. I have used the iron on strips for shelves in kitchen cabs, and they are ok. I have had to go back an reheat them, the edges can be a bit frail, just not something I wuld recommend.
No, the base/legs do not have to sit out. have seen it multiple ways. Sometimes it is nice to have some offset for a transition, again, personal preference.
As for the decorative panel on the side, absolutely. Be careful if it is solid wood though as you cannot glue a large panel of solid wood to plywood. Plywood shrinks and expands very little to humidity compared to solid wood.
Regardless, you have alternatives, some easier than others. It is all a matter of personal preference.