Help Me Understand

I have a background in accounting and finance.

I myself don't have much experience with Bitcoin since I've always been a skeptic, outside looking in.

I might look into it more closely, if anyone shine further light on a couple of questions, from a guy with basic accounting knowledge but none about the cryptocurrency space. Sorry if these were asked before.

1. It's called cryptocurrency but aren't each user 's transactions added to the block since it's just a digital ledger that keeps a record from the start of the blockchain. Or a simpler way to put it.

If I handed a dollar to my friend in California and my friend hands it to his other friend and then 10 steps removed the dollar ends up let's say in a pocket of a guy Florida. There's no proof of who held the dollar but in the blockchain, isn't there user IDs embedded on the block chain , meaning there is digital proof that at one point you held the crypto curreny even though it is encrypted, is there a digital signature?

1. There is a limited number of Bitcoin, 21 million I believe, but my friends told me they buy partial coins since they cannot afford one full coin. The problem i'm trying to figure out is if you start to buy partial Bitcoin, isn't there just a unlimited amount of Bitcoin then?

There's an infinite amount of numbers between 0 and 1. I think most people understand this concept or google if you don't. So are the rules of Bitcoin, Are they set in stone or are they ever changing? There's smaller units of Satoshi which then make it 2.1 quadrillion which is more the world economy of 100 trillion USD.

Saying there are only 21 million is not honest and since it's digital, you can break it down as much as you want and transact it. Meaning try buying a Ferrari with pennies, it's doable but definitely not practical or typical for obvious reasons but with crypto it definitely is.

Another way to put it since it gets compared to gold all the time . Everyone agrees there is limited supply of gold but it's not realistic or anyone would melt gold to microscopic levels to transact it ( I'm talking 0.000001 gram or something so small you would need to bring laboratory equipment to measure). With Bitcoin, it's doable since it's digital, The practical limits of the physical world don't matter since its digital.

These are my two big ones. I have a bunch of other ones but this is what was stopping me from investing. Can anyone shed some light?