Before you export, your timeline needs to be set to HD 1920*1080. I'd suggest you use a frame rate of 60P but given the Studio 15 doesn't have these options, use 29,97.
You need to export the file to HD 1920*1080, frame rate as above.
If the pictures are still pictures (that means not even using Pan and Zoom) the bitrate will not make any significatnt difference as long as it is not too low. Hiowver, give that you are using such an old version of Studio, the maximum looks as if it is 12Mbps. That should be fine. What you can do is make a few test files. I'd guess that you can go quite a bit lower than that without noticing a drop in quality.