Hello,
great that Fusio helps you. Regarding your questions:
1. Could you tell me which SQL action do you use in this case. Also can you show me the log/app.log to see the actual error, you could also set the APP_ENV to "dev" to see the actual error.
2. In general this should be only JSON encoding, so if you JSON decode the data on your client it should have the fitting format. If this is an encoding problem you may wan to check the character encoding in your database, it should be UTF-8.
best regards
Christoph