Immutable blocks

1. is not even a thing let alone be important. first of all there is nothing wrong with having ASICs and being able to use them, secondly there is no such thing as "Anti-ASIC", some coins fooled their users by this "buzzword" but in reality they are "Anti-bitcoin-specific-ASIC" in other words you can use ASIC to mine them but not bitcoin's ASICs.
2. as long as this is not a weaker algorithm, it can be good but i wouldn't put it on the top of the list. it belongs down.
3. not mandatory.
4&5. these can be added as second layer to most coins so not so much important. not to mention that things like "cross chain" are only useful for traders!
6. so far i have no seen any usage for smart contracts although the idea seems good. so i'll say not important

7+. being Decentralized, boarderless, permissionless, immutable, secure

Yes, very important element that you mentioned in the Blockchain system,
Meaning: Blockchain can bring to the most positive things, with technology transparency and efficiency, I think a lot of things can be overcome with blockchain,
in other words, blockchain like technology enters almost all sectors,
For example: When you buy coins like bitcoin, in this case the computer that is connected to the blockchain, can record and valid data automatically. Therefore, a little mistake, fast, and easy.

For me, I like the "Anonymity" feature of the Blockchain System. I like being unknown using the system, doing stuffs like buying and selling coins like bitcoin, without anyone knowing your true identity.

Let me be one of those greedy shitters:

Mass adoption would be the most important feature.
I don't really care how useful would be the other new features while my BTC savings worth nothing and can't be traded for anything.
The other things like immutable blocks, decentralization etc. are ofc important but they are just secondary things until we see good demand in cryptocurrencies.

For my laic tech knowledge the most important feature is smart contract. I am absolutely sure that blockchain, crypto and Bitcoin would not reach that breakthrough it has. It would still just be somewhere in the dungeons.
And so much useful applications this feature has. It will definitely stay in our lives...

I’d say a distributed ledger since it helps in recording of each transaction. Every user then is able to validate transactions and has its own personal copy

Even though this feature could also be considered a disadvantage I think anonymity is one of the key factors why people like blockchain system. Before blockchain technology was created it was pretty much impossible to transfer money online to another person without needing to reveal your information to the bank or payment system and thats now possible because of blockchain.

but mass adoption is not a "feature" of something. it is the result of having other features. for example because bitcoin is a decentralized currency it is being adopted and its price grows not the other way around.
you first have to create something useful then have people use it, otherwise you will be left with some altcoin that nobody cares about or uses and the only thing you can see is temporary pump and dumps before it dies.

Borderless transactions that are censorship-resistance are on the top of my list. Why should anyone be able to stop you from moving your wealth from one country to the next? <You worked for that wealth>

Pseudo anonymity will be my next feature, because everyone needs some level of financial privacy and Bitcoin offers this to them. <Why should the government know, when you buy naughty underwear for your special person?>