Have anyone make asset selling site where can put asset / contact details if want sell some asset what own?
Not sure if I understood you correctly but
https://counterwallet.io/ should do the trick for you. There is a decentralized exchange in place to list/buy/sell your tokens
What is this talking about side chains? Can that really risk counterparty future later?
An alternate way proposed to execute these transactions without bloating the blockchain ledger which is already several gigabytes in size. Counterparty devs have raised security concerns over such an implementation.
Risks to counterparty? Not while sidechains remain unproven and theoretical. Tomorrow if that changes, Counterparty team have shown to be extremely adaptable, as recently demonstrated by the integration of Ethereum programming language on the counterparty platform.
What is biggest possible problem what devs thinking can be front of in future? If not count SEC or some USA ban all cryptos..
Anything is possible. There are however no immediate existential threats
