Hi Vanessa, we will provide you with a list via email.

Hi Alvin/Nick, as we have an ongoing challenge to keep all our very diverse Tridion users on the same knowledge level, I prefer these things to be configurable for the whole group in one go; hence on schema or template level. We will look into tips given. Can I check all available hotfixes for 10.0 somewhere?

Yes, the ordering of component templates is alphabetic in 10.1 and also in 10.0 if you apply hotfix DXUI_10.0.0.38967 or later.

As you point out, setting the TRIDION_SITES_DATAPIPELINE_DISABLED environment variable to true will hide the None option (selecting a component template becomes mandatory).

We don't support custom ordering, but it is possible to limit the component templates shown in the drop down using region constraints.

Nice idea. At the minimum the Component Template ordering should match the Classic UI. Consider reaching out to Support to see if this could be addressed and fixed as a bug. I recall at least one other list being fixed that was showing out of order.

In terms of an enhancement, is custom ordering something that makes sense to you at a Schema level or per individual user?

Also, the "None" Component Template option is part of the data publishing feature. Your team could consider disabling this if it's not used at all. See related idea and comments:
Disable 'Add' button for the Component Template option of 'None' when you disable template-less publishing on the schema