I can answer questions related to Alter command. You can do any of those as Alter commands will execute one by one even if you alter 4 alter commands at a time. So it does not matter.
I looked around here and couldn't find anything related to this "database conversion" with the update.
Is it something that everyone updating had to do?
I have not done a manual update in using Chevereto as it does the auto-updates for me and for most people. And to my knowledge minor upgrades never required database conversion.
Do post from which version to which version you are performing the upgrade.