the 3 situations are exactly the same.

If you send coins to an INCORRECT but VALID address they are gone forever.

Bitcoin addresses have a 32 bit checksum so the odds of creating a typo which is INCORRECT but VALID is about one in 4 billion.
Still it could happen.  If you are copying and pasting the odds are essentially zero (that you could drop or add an extra digit and still produce a valid address with the same checksum).

The much more common problem is doing something stupid:
For example thinking you are sending coins to yourself (i.e. your address) but copying the last outgoing address and sending a boatload of coins to someone you sent coins to before.
Obviously the network can't protect you from that.