Fate of locally stored music files after you turn apple music subscription on

Very interested to join apple music. However, I have thousands of songs ripped from my cd collection in lossless alac format over the years.

when you sync your library over icloud accross your devices, what happens to those local files?

Do they remain in place on your hard drive or are they removed?

In case syncing for some songs choses versions that are not related to the original song (it apparently happens) can you manually curate and seek resolution?

when streaming from the music app, can you choose between your synced library and your locally stored (if that still is in place after signing in and syncing)?

Can you still continue to rip songs from cd’s and add to your library after you joined apple music subscription?

thanks a lot for any clarity on this,

m