Hello Warren,
1. You may not able to do the UDIs while the rebalance is still in progress.
(Tablespace state 0x10000000)
2. Technically it could be possible to have the mix.
3. Not necessarily.
The mentioned steps are OK. But you may also consider to try following steps on a test server, where the database is already on 10.5.
- Create automatic managed tablespaces (via dbacockpit)
- Do online table movement using latest version of DB6CONV. (SAP note#1513862 )
* A guide is attached in the note.
Kind regards
Maria