Scammers impersonating other people would not be solver by Bitcoin neither stacker news, you must accept that is something that is going to happen whatever you do.
Also splitting should be automatic to make the process easier. If an address isn't found, then the amount is divided among those address working.
  • Someone post content and the address of the creator.
  • someone respond by "tip 100"
  • 100 sats are send to that direction.
  • If more than one address is posted, then tip is splitted between the number of address.
  • if one address fail, payment es splited to the others ones working.
The part about splitting should be the more complex. Eventually could be simplified by "tip 100" where 100 sats are sent to every address.