2) The full server file name should be available through bindings as well as the file name and extension individually.
3) This is correct it doesn't have the option to ignore or cancel the upload if the file exists, only to overwrite or rename.
1) Create a DB connection and use the logic I noted. Then try to find any table when you first open the Update Record Wizard. You'll be able to selection your connection file but no tables will be offered. It may be that no DBs are offered but since I've moved on from that roadblock I am not sure.
2) I don't see it. Screen shot attached
3) Please consider passing this to the powers that be as a viable update/enhancement. An update page should be able to actually update without requiring every value to be changed. Having to bounce to a second page to change out an image is not as efficient as it could be. Check out your copy of ADDT (if you have one) as i've done this on a number of prior occasions. But since Adobe is planning to shelve that product, it's forcing some of us to buy WA extensions (or properly learn PHP and save our snippets as we should) as a replacement. So if you have this, we will not need to learn the means to accomplish this on our own (counter productive to your Marketing teams goals).