Using a hash as a private key is not as efficient as using OP_RETURN because it will require more transactions. You'll have to send some coins to the derived public key to prove existence of the hash, then you'll eventually want to transfer the coins back (2 transactions = takes more space).
Using a hash as a public key will just "burn" the coins (which is bad - increases deflation).
OP_RETURN has been created for the purpose of storing data in the blockchain, the inputs become fees and are given to the miners (no money is lost).
The "2 transactions" thing is a feature; not a bug. You can leave the funds there for scavengers to sweep as a verification that the process is working correctly.
Using a hash as public key is indeed bad, but not because of deflation. Decreasing the total supply of bitcoin is like giving a donation to all holders proportional to their holdings. A "burn" is bad because it permanently increases the pool of unspent outputs. This is a burden on full nodes.
The block chain was never intended to store data beyond what is necessary to record the transfer of funds between addresses. The private key method, although hack, does not betray this purpose.
This project is a rip-off, likely backed by UnSavoryGarnish
i. Users should be highly suspicious of the fact that you require registration. That's not unlike regulators desire to taint bitcoin addresses with personally identifying information for the purposes of tax collection and cash flow restrictions. Your justification for the registration is moot considering that the same end can be met with the use of
GPG contracts.
i :
#bitcoin-assets log