Is it possible to develop a Microsoft Teams Bot for interactive communication without going through the step of registering it with Azure Bot Service. If it is possible, are there any Python examples of doing that?
Nope, this is not possible at all. There's tight integration between the two for bots. Importantly, there are two options when creating a bot in Azure:
Bot with Web App - this includes a bot registration AS WELL AS hosting using an Azure Web App
Bot Channels Registration - this is JUST the registration, which allows a very decent free option, and then also allows you to host your bot in a different Azure hosting option or anywhere else you like even (e.g. AWS). So, this is all you really need to use and the free allowance might well be sufficient.