Dear Gé,
best thanks for your interest.
> 1. Do you think AutoHotkey could replace MSKLC, i.e. create a
> complete alternative for a custom keyboard?
If you consider a Jaguar S Type a replacement for a Fiat Panda: Yes. :)
> 2. This could be amended by changing the quotes from "standard dead keys" into
> such an expiring dead key as you describe.
No problem. This could be done with an automated backspace inserted
via AHK script, to mention the least invasive option.
> Thanks for the post! It’s off-topic within this Ukelele group, of course,
> but we don’t mind too much :-)
If it's ok for the group, I don't mind. Personally, I love to have a
look 'beyond the plate's edge', as we'd term that in German.