Reply to "as only"

Thank you very much, DocV,

I'd like to ask a follow-up question if I may. What will happen if we take 'only' out of 'as only'?

Who stole your mother's ring?
6) It is possible that the butler did it, as  he could.

7) I saved them, as I could.

8) She played the concerto as she could.


Do those sentences work?

Are '6' and '7' ambiguous?

Does '8' imply that she didn't play it well?