regarding payments for posts. there are several options:
1) require be logged in for sending post you can pay for. that way site would need to store user ID of every post even if other users can't see your nick. also you need to check whether user was logged in to send payment (to get the wallet address) which partly deanonymise the posters.
2) generate session with wallet for each user and store its ID for every post. can pay for every post but site will always know your ID and which posts you send. there're ways to do it now as well but they're not stored in DB. though site can create new IDs e.g. every day so you won't be able to pay for post elder than 1 day. there might be also issue with session invalidation e.g. if you don't refresh the page and just sending posts. you need to get new session cookie even in that way.
3) generate wallet for each post on client site and send its address to the server. so you can pay for every post and client can get the money with its private key stored in e.g. localStorage.
4) same + give the option to specify your wallet generated offline. site will know your ID but there is no way to steal your private key even with malicious JS.
#4 seems to be the best, though site can cheat by showing different (its own) wallet on sending payment. there is no way to really avoid this because it might be done only for small part of transactions. even if user will complain he didn't receive anything, he might be just a troll. and you can't prove it with screenshot. it might be partially avoided with publishing key near each post so if you see it's different (e.g. from different IP) you can start complaining right away.
if you specify offline wallet it's almost the same as ID though, because it would be the same for all your posts. but it's more secure. though if payments are not that big (<$1) and you move them right away from your in-browser wallet to your main wallet it might be ok. also it might be not so convenient to have tons of wallets if you post more, it's tedious to move the funds to your main one.