Is there a way to attach my email address and bitcoin address to my eos account name? And also be able to query this data from a block explorer? Basically looking for a way to set a property value to an account name. Is this even doable without using IPFS to store this string data?
If you want, you can create a smart contract to do this, which would be very much similar to the
regproxyinfo contract (https://bloks.io/account/regproxyinfo). In this case, any user may send action to the smart contract with desired metadata, and the metadata will be saved into a multi-index table. When you want to query, just query the multi-index table as you want. Like: https://bloks.io/vote/proxies .
Sign a message "This is my BTC address: xxxxx" using your EOS private key
Publish the signed message somewhere off-chain, you do not need to pollute blockchain itself with metadata