Can DELETE ALL macOS data/passwords of my MBP2016 - but not uninstall macOS

Sign all users out of their Apple IDs.

Create a dummy admin user and delete all other users selecting not to keep their Home folder. That will remove all user created data.

Once you get it back, recreate your "real" admin user, migrate your data back (I'd simply copy it back the old fashioned copy and paste method) then remove the dummy user.

Immediately make a backup.

lsepolis123 wrote:

1

Sign out from Apple ID - all data Notes, emails, iCloud data, are gone & removed from the Mac, correct?

I don't use those items so I don't know. I believe when you log out of the Apple ID it presents you with an option to keep local data or to delete local data.

2

AFTER I erase my MacBook Pro, Monterey --- needed to re-install macOS...? instead can I ... >>>

Needed reinstall --- can restore [macOS + apps + data] from TM backup instead??? 1. without reinstall???

I don't use TM, but I believe if you erase the drive, then you need to reinstall macOS. Then on the initial setup of the OS, you are presented with an option to restore from a TM backup. You need the full OS install first in order to have proper boot options and partitions/volumes.

Mac errors: like Fans battery etc. hardware problems -- 1. can handle/fix even MacBook Pro is NOT installed macOS...?

It may depend on who does the repair. Apple no longer requires a login account. If Apple or an AASP wants to troubleshoot a possible OS related issue, then Apple now has techs do this with the owner present so the owner can supply the password when needed so your password is never revealed and your data (if any) is never left alone with a tech. If Apple receives a Mac with no OS or a broken OS, then Apple may perform a clean install of macOS (who knows which version though). This would be a question for the repair shop or Apple.

For debugging hardware problems, is it better not erase the OS MacOS, and just DELETE DATA.... as said above...? 

It depends. If a tech has access to a user account, then seeing how the system works with the installed software is always useful since many people tend to have software issues, but how a clean install works is really all that matters in the end and is Apple's preferred method. Also see my note above.

Also, after fixed will Not needed to install macOS...correct?

It depends what the tech does. If Apple reinstalls macOS themselves, they may install the OS which shipped from the factory, or perhaps Monterey. You just never know. If they don't touch the OS on the SSD, then you should not have to reinstall macOS.

Also, exist danger of failure during erase of macOS and have to replace SSD... correct?

Only if the SSD (or Logic Board) is bad. If the Logic Board and SSD are good, then there should be no danger erasing the Mac, other than finding out the backup is bad.

@ku4hx has provided you with a solution that meets the requirements of your original question. Your personal data is stored within the macOS user account(s) and with an SSD after the data has been deleted, the data is no longer accessible as long as you select the option to delete the data in those user accounts. The other option available you listed as a link in your own post.

If you want to delete the apps, then performing a clean install of macOS is the fastest easiest method to do everything you want.

If you want quick & instant responses, then the forums are not the best option as we are just other users such as yourself volunteering our free time. Real life gets in the way and can keep someone from responding back for days sometimes. Contact Apple support directly using the "Get Support" link.

Sounds like you have a bad fan or possibly something is stuck in the fan. I can definitely hear the fan bearing before the louder noise.

Most USB sticks are extremely slow, even USB3 sticks so this is not surprising. Even a USB3 external hard drive is usually faster than most USB sticks. However, if there is any temperature or power issues with the laptop, then the CPU will be running at idle speeds of 800MHz, instead of 2.x+ GHz. A USB3 SSD will give you the fastest transfers.

I don't use TM, but when I used Migration Assistant there was an option to migrate "Settings" both within the user account(s) and system wide. Most data and app settings should be contained within your user account(s). Only apps which modify settings (aka preferences) system wide for all users will have their settings (aka preferences) stored in the System area. You are not specifying whether you mean app preferences (that is custom configurations you made to an app), or just your regular user data. Sometimes the former will be stored separately and other times within the document itself depending on the app.

Maybe if you are a bit more specific another more knowledge contributor familiar with TM can assist you.