Unfortunately, ID does not support a leading tab for footnotes. It's my preference, too, to right-align the reference marks (and numbers in lists, etc.) and then left-align the text. Other than specifying a fixed negative first line indent, I haven't found a way to align note symbols this way, at least, automatically.
You can define tabs/indents for the footnote style and then manually tab in the symbol on each. That's as close to an automatic solution as I know of, short of GREP styles or a script.
(Could a GREP style be used to insert a leading tab? Hmm.)
We use a figure space to push single digit numbers over to the right.
Adobe should let us align the position of bullets/numbers in lists.
But I think pigs will fly before they give us that feature!
Yes, and I've used two different styles for this kind of alignment, in TOCs etc.
But all these workarounds would be unnecessary if the setup simply let us put a tab in the prefix of lists, footnotes, etc. I can't imagine there's an important (unsolvable) reason for this rule; it seems very arbitrary. It's just another white space, after all, and prefixes and suffixes both support WS.