Nim disallows tabs entirely, and in Python 3 it's an error to mix the two in the same file. So those errors can't happen anymore.
Out of your list, the only one that seems like a real problem is recreating blocks if the code lost all formatting.
Out of your list, the only one that seems like a real problem is recreating blocks if the code lost all formatting.
If a language either disallows tabs entirely or will refuse to run/compile code that mixes tabs and spaces in the same source file, you obviously can't get errors related to mixing tabs and spaces.