I can answer this to the best of my understand which I will admit is not much.

open.btc is a open. asset provided by openledger. They have in their statement that they are backing the open.x(btc,eth) with equal value of btc open.x(btc,eth).

You can generate a deposit address for safekeeping with the CCEDK dac openledger.

You can then trade your Open.BTC for things like maker DAO (A DAO operating using Graphene and the Ethereum Blockchain)

https://bitshares.openledger.info/#/market/MKR_OPEN.BTC

Or back to BTS here:

https://bitshares.openledger.info/#/market/BTS_OPEN.BTC

Openledger is a registered Danish company and I imagine it would not be fun to have to account for missing btc and with that said I think Ronny puts a great deal of attention towards the latest security tech and knowing that your and if you look at coinsbank Ronny Boesing has a lot more up his sleeve.

There are also a number of UIA (User ISsued assets) on the Graphene blockchain that do not have open. or meta. These can be organizations, companies, celebrities or whatever that issue these tokens on the graphene blockchain.

Think Cadastral Bitland, PEerplays, OPEN.X, BitTeaser, MKR, blockpay, bunkerchain, ..

Overall I think bts is a cool eco system that has a promising future assuming the commitee can get shit done in the growing market.

Thats my not so educated rant on BTS. :D