The PI System is not meant to be used as a control system. Please read through KB01295 - Risks of using the PI System as an input for a control system
Output PI Points
Ouput points to the BACnet device are supported. See page 57 in the User Guide for additional details
The BACnet interface does not support autodiscovery with AutoPointSync and will require tag creation/configuration. I would suggest taking a look at the PI Connector for BACnet which will perform and an autodiscovery and will handle the PI Point / AF Element / AF attributes creation but it does not support output points.
Other interfaces or tools
See point above
You can create simple analysis using the Asset Analytics feature in AF. In general, for complex predictive analysis, you will want to feed PI data into a dedicated software and import back to result.