Can a hero give money to another adjacent hero? Or only items and potions? Thank you.

Only items (including potions). Must be adjacent, 1 movement point per item given, and you can only give (not take) items during your own turn.

And what is about Mata & Kata? Can they take an item from and adjacent hero? Or must they receive the item from him?

gran_orco said:

Items can only be given by the acting figure (or Mata and Kata), not taken from another. So the hero would have to give an item to one of the ferrets on his turn, and then the ferret in question could run over and hand it to someone else on its turn. Or hold onto it for a while, that's also valid.

RTL is easier in that regard, as its a party pool of money.