With respect to your second question about losing keys - it's the same as losing keys to a numbered account in a bank. It's possible but unlikely, and if it happens despite warnings about backing up, and giving copies to close relatives, c'est la vie. With respect to parts not being able to be sold, again, I would refer you to what happens without the blockchain. If you buy a part of a building and just disappear, it's not possible to sell in whole, but that does not mean that the rest of the owners will not receive their rental income, and can't resell their flats.
If I lose my key to my bank account or my key to my bank vault, I can go to the bank, identify myself, fill out some paperwork, pay a fee, wait for a few days maybe and I have my belongings back. The bank keeps my personal information linked to my account / vault. If I disappear, my heirs will inherit my belongings.
Why would you refer a blockchain-idea to what happens without a blockchain? Isn't the whole idea of a blockchain that it is decentralized? There is no central entity that keeps track of who owns which token. And since the tokens are being traded in exchanges all over the world, there is no way to do that.
I totally agree that if you lose your key, it's your own stupid fault. But if it happens to >10% of the token holders it cripples the other 89%. It is a blockchained contract, right? So the rules cannot be changed anymore. And since there is no way of knowing who owns the 'missing' 11%, the other 89% can only receive rental incomes like you say. But they miss out if someone offers a huge amount for the whole building.
In a numbered bank account the name of the holder is not revealed, and the bank does not hold the name, rather access to the account is granted to the account holder via a code-word, which is similar scheme to that used in RSA cryptography. You're somewhat confusing distributed ledger with the word blockchain. All distributed ledgers do not have to necessarily employ a chain of blocks to successfully provide secure and valid achievement of distributed consensus, a blockchain is only one type of data structure considered to be a distributed ledger, where each block shares data with other blocks and forms a P2P network collectively adhering to a protocol for validating new blocks. Nonetheless, if you read our whitepaper (
https://atlant.io/assets/documents/en/Atlant_WP_publish.pdf) carefully you will realize that we at ATLANT are building a completely distributed ledger without any centralized hurdles such as going to the authority upon every transaction which Propy does (which in essence is not changing the system, just slapping the word blockchain to make it sound fancy, and does not really fix the existing problems). ATLANT plans to initially trade PTOs on ADEX exchange based on Ethereum smart contracts, which should answer your second question. Per the last part, as already mentioned, we are not changing the status quo, in other words in an existing infrastructure, even without tokenization, if a fractional owner does not sell for long periods of time, 100% of the building can not be sold, however the remainder can be.
Eakamc2, I would like to commend you on so many great questions for a user who just joined bitcointalk yesterday and is so keen on ATLANT, that all 6 of of your posts appear on this thread. With this much thoughtfulness and enthusiasm, I would like to direct you to our bounty thread, where you can channel your energy and earn some ATL:
https://bitcointalksearch.org/topic/closed-2053308