Will "pirated" apps be auto delete by Windows10? Would it know they are pirated?
No. This is a conspiracy theory that people who can't read have gone off on.
Firstly, there is nothing actually happening, all this is because of a line in a terms of service:
"We may automatically check your version of the software and download software updates or configuration changes, including those that prevent you from accessing the Services, playing counterfeit games, or using unauthorized hardware peripheral devices"
This not NOT in the Windows 10 terms of Service, this is in the terms of service for XBox & Games made by Microsoft.
MS's terms of service say they can stop you pirating MS-written games. MS are not actually DOING anything. THey just gave themselves the right to protect their own software.
That kernel of truth has been exploded into the lie that Windows 10 deletes pirated software. Utter hog-wash!
what about music? I'm told iTunes will delete those music wasn't purchase via iTunes?
Absolutely not. More nonsense from the tin-foil hat brigade.
I believe the teeny tiny kernel of truth in this one is that there was A BUG in the first version of Apple Music that accidentally deleted some songs in some cir

stances. Apple very quickly released an update to fix the bug.
I have now Windows10 ready to install but having doubts because some of my apps are not...err... totally legit.
I wouldn't let these conspiracy theories sway your decision making. Concentrate on the real questions like - is your hardware good enough, do drivers exist for your printers and stuff, and do you want the changes to how the OS looks and functions that come with the update?
B.