I have a couple of points on this topic.
1) Here is the documentation on how to move to a new TIC server. https://support.quest.com/technical-documents/toad-intelligence-central/3.3/deployment-guide/11#TOPIC-686174
To move you need to move data files from one server to another that has the same TIC version. Then you can do the upgrade of TIC as a second step.
2) There currently is a bug in moving automation scripts over to a new server. The decryption of passwords is using a private key generated on the server that cannot be moved. We are currently testing a fix for this. QAT-12502 this patch fix will be available through support in the TDP 4.3 code line.
3) Moving the owner of objects is a planned feature for the 4.5 release. i received another manual script for this that I am testing.
These are a lot of changes you are planning. I suggest you make then one step at a time.
Suggested steps would be:
a) Upgrade TIC. What version are you upgrading from?
b) Wait for fix in step 2 and move currently running scripts to new server of same TIC version
c) Change owner of scripts.
All of these steps should have backups of all files and let them run for a few days in between to confirm that step is stable.