Whether your broker can see your stops has nothing to do with them being a market maker or not. Rather, it has to do with whether your stop orders rest server side or terminal side. If your stop rests server side, then your broker can see your order. If your stop rests terminal side, then your broker cannot see your order.
If you use the default stop order functionality built into most trading platforms, then it's most likely this order type will rest server side. The advantage of server side stop orders is that even if your own trading terminal loses connection, your stop order can still execute to get you out of a losing trade when triggered.
However, if you are concerned about your broker being able to see your orders, there is a way to program a terminal side stop that will only send a message to your broker's server, if your stop price is triggered. That said, it's important to keep mind that, market maker or not, what matters is the quality of your broker.
Generally speaking, you should consider brokers regulated in major financial centers appropriate for your region. That can go a long way to addressing a lot of the concerns you have. The advantage of trading with a well-regulated broker is that there are minimum standards both financial and trading, ongoing monitoring by the regulators to ensure compliance, a framework for handling complaints from customers, and the power to enforce actions against regulated brokers for violations.
For example, the CFTC and NFA set the requirements a broker must meet in order to offer forex trading to US residents. Though not an exhaustive list, this membership application will give you an idea of some of those requirements: https://www.nfa.futures.org/registration-membership/who-has-to-register/rfed-applicants-compliance-requirements.html
- In the US, forex is regulated by the CFTC and NFA, and brokers are required to maintain net capital of $20 million.
- In the UK, forex trading is regulated by the FCA and funds are protected for up to £50,000 per client by the FSCS.
- In Canada, forex trading is regulated by IIROC and funds are protected for up to $1 million per client by the CIPF.
You may find this earlier discussion helpful in understanding the different methods retail forex brokers can use to execute the orders of their clients: https://forums.babypips.com/t/who-is-the-counterparty-in-an-exchange/131392/20