Branching Scenario customization limits

I am working on a new project that I want to use the Branching Scenario to tackle. I have a few questions on what the limits I can do for implementation.

1. Can I customize the start and end screens? I want to change the "Start Course" to something else, and remove the "Restart" at the end
2. Can I implement any other "Proceed" option than the built-in button? Ideally I would have something like the image hotspots, and a button in the hotspot pop-up to continue to a specific branch (instead of having the user click the top button, then click a text link)
3. Is there any way to not show scores at the end of each part, and only show a score at the end?

My use-case is that I want to create a grocery shopping exercise - the user moves forward through aisles of the store, and they need to choose items to buy. Final scores are based on the items in their cart versus their initial shopping list. I am trying to make it a bit more immersive by letting users browse aisles dynamically (through image hotspots) and progressing to the next scenario through a button on that hotspot.

I do want users to be able to go back to previous screens, but I do not want to allow them to re-try at the end (score will save once, then push the user forward to a different module as soon as we get the final xAPI info)