Tons of questions here, but sure I'll give it a go.

Any autonomous or nearly autonomous hardware device would be taxed. Exceptions can apply. Maybe autonomous tractors are not taxed because food is needed, but unemployed farmers also need to be cared for.

As to the code question and m365, maybe, maybe not. It may be reasonable to tax all cloud automation as a whole, or maybe just all SaaS, leaving IaaS and PaaS out of it. Exceptions may apply.

The tax would be on the good or service forever, yes. If you displace human workers with automation, then thry need their basic needs met for human decency, but also so they don't tear society to pieces, justifiably in my mind.

Incumbent companies using automation may have an advantage, but only until they use a new robot or new automation. That advantage goes away if they are stuck 5-10 yr behind to avoid a tax. If they want to keep avoiding it, newer companies using taxed but getting a huge productivity booster will surpass them. That will incentivise them to use the tax producing goods or services and remove any initial advantage.

I think I would also be okay with "no tax until you hit X automations" as well. You clearly can't give tax breaks on employees, as not employing people will be the whole point of this, but you could likely work it out.