Recovery requirements after changing pc + Protect encrypted folder

Hello, new here and would need to ask 3 questions:

1- I want to ask what do I need to recover my files after moving to a new pc.
Do I only need the password, or also the full set of recovery words?

2 - Another question, Is there a way to password protect the encrypted folder, so that only Cryptomator can open it?
I mean… If somebody modify the content of my encrypted folder, after that cryptomator will not be able to unencrypt correctly its content. Is that correct?

3- If your project in a few weeks closed down activity and no more releases of the software is are provided. Would there be a way of recovering all my encrypted data? I mean: Is open sourced your encryption algo?

Thanks a lot in advance.

To 1)
You just need the encrypted vault files available on you new pc. If you have them online just sync them tonality new pc. Thwen install cryptomator on your new pc and add your existing vault. Unlock with your password.
See documentation here: Adding Vaults — Cryptomator 1.7.0 documentation
Your recovery key is only used if you want to set up a new password because you lost your old one.
See documentation here: Password And Recovery Key — Cryptomator 1.7.0 documentation

To 2)
No. Like any other Programm, cryptomator needs access to the encrypted vault files. Means also the windows user need access to the encrypted vault files. Further more the sync client needs access to the encrypted vault files. So you can’t protect them to only work with a specific app. The encrypted vault files online are just files. Everyone who has access to your online storage has also access to your encrypted vault files. Yes, if anyone messes with your encrypted vault files, this will mess up your vault. To cover this risk you need to have a backup strategy.

To 3)