And I hope I don't bother you, but could you please tell me just briefly wether what I said under points 2-4 is *generally* right? You don't have to go into detail, I would just like to know that I'm not entirely mistaken. But if you don't feel like answering, no problem! I perfectly understand it!

Yes, it seems generally right to me. Use -choH when you want to describe an action changing one state into another, not just if you describe an action that might involve a change of state at some point that you're not talking about. When you say jIbwIj vISay'nISmoH, the washing you're talking about logically implies a change of state from unclean to clean, but the action you're trying to depict isn't the change of state; it's the act of washing.

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SuStel
http://trimboli.name