Morning,
Personally I see a few possible issues that could be causing issues. When you removed the datastores without detaching I assume you mean unmounting. This could leave your datastore heartbeat in a bad situation. I suggest the following course of action to resolve the issues.
1. Check DRS settings and make sure the datastore heartbeats can be on any of your remaining shared data stores
2. Reboot each host in order clearing any oddities
Start to diagnose any additional issues you see... I personally doubt it's a database problem or that the problem will be resolved with shrinking. Try to change as little as possible in your troubleshooting.
Please let me know what results you get after the reboot.
Thanks,
Joseph