Correct, but the nuance of moving the decimal requires you to understand the hard cap. You can move the decimal over infinitely & yes you'll be creating a smaller, smallest denomination - but you'll never reach the hard cap of 21M just as close as you can get to infinity ♾️.

There is no decimal. Your wallet software just shows it to you that way.

No, there is no such thing as "a bitcoin" or "a satoshi", in the software, in memory on your computer, or in the protocol. This is actually crucial, and not just semantics. If each satoshi were an actual thing, then they could be traced from inputs to outputs. All that exists is an accounting mechanism of (output measured value - input measured value).

Great point.

Reification :)