Is it easy to remove encryption's password prompt on boot if I don't want it anymore?
It's not quite easy, but rather complicated to remove encryption depending on how much data you have on your phone.

Removing encryption, AFAIK, requires formatting /data partition. So all you have to do is


Copy out all personal files from internal storage (assume you have a shared storage)
Make a backup, if you want to continue using the phone ASAP
Format /data
Copy everything back
Restore from backup


The encryption removal itself is, rather fast (a few seconds). The only complication is backup &amp; restore.

Performance issues:

The encryption is done at real-time, so whenever an app wants to read or write data, enc/dec is done before reading from/after writing to disk. This, however, does not have a great impact on CPU. I haven't noticed a great performance degradation with encryption (with my OnePlus 5), so I believe it's safe to have encryption enabled without worrying about performance issues on modern phones. It has always been complained about by Nexus 6 users. You'd better stay away from it if you're using a phone with eMMC storage and a non-flagship SoC.