I am guessing the counter party can see the executing broker on the other side of the transaction, unless the trade is done in a dark pool. Is that correct?
They do not get that, as far as I know. Not sure why the CME would share that. You can contact them to confirm. Also, I'm not aware of any futures dark pools.
That's going to depend on the exchange and I'm not an expert in the various trade message formats used each exchange out there, so I can't say definitively. However, as an example, CME's MDP trade execution messages do not include identifying information about the parties involved in the execution. It includes items such as order id, quantity, price, but nothing to identify a specific entity associated with the order. This is not to say that no exchanges provide identifying information. Because of how many exchanges are out there, you're going to have to provide more information about which exchanges you're dealing with if you want a definitive answer -- or to be even more sure (vs trusting some randoms on the internet), you could get the message specs for each exchange you care about and read for yourself. My guess is that for US futures and equities exchanges, the information is probably not supplied, but that's really just a guess. Alternate trading venues, non-US assets, etc, I assume there's something out there that provides identifying info.
I thought I read some where that market makers or high speed traders were given the broker ID's of the opposite side of the trade. I guess not then.
CME has Level 3 MD. You can see the size of each order at each price. It does not say what the broker name is or your account#.