2. According to the manual the save/load only exists in the bios 0 monitor, and not in Basic. At least not that I can see. I do not know how to save/load Basic programs. The Basic is only a single 4k rom which means it has very few features.
1 & 3, don't know yet. The keyboard has various issues, might have to rewrite it.
Thank you for the answer. Bios 0 is the 40 column version ?