NEX-3 upgrade questions
1- I have an extra, non-Sony battery that works great for my NEX-3. Does the F3 use the same battery?
Some of the early non-Sony batteries only work with the NEX-3 and 5.
2- I am going to assume that due to the screen differences, that my pop-up screen cover for my NEX-3 is not going to fit. Is there one available for the F3?
It will almost certainly fit, but may not clip on as perfectly as it did with the NEX-3. The holes at the bottom of the screens vary from model to model. You may have to secure it at the bottom with a bit of tape or possibly press it on a bit harder. Probably nothing you can't fix with a couple of minutes modification.