I feel a bit like you're framing mediation in the wrong light, and I think that's to your detriment.
You need to remember that a mediator isn't an authority. They have no power to make decisions for you, and their job isn't to pass an opinion about your case to try and influence an outcome. Their only job is to keep you and the ex civil and focused on settling the dispute at hand. They don't particularly care what the dispute is, nor what you decide about it, just that you do so in a way that keeps you focused on the objective, instead of descending into a mud-slinging match that is totally counterproductive.
Remember, it was your ex who called for mediation, not the mediator. The mediator is not on your ex's side, or your side, or the side of the Court. The mediator is just the person providing the service, no different to the guy who drives your taxi or the waiter who serves your food. They can't answer questions about your case, because it's not their job to have any personal investment in it. If they did, they wouldn't be the objective third party that they're meant to be.
They're not asking 'Are you with me?' to be condescending; they're asking because they are trying to make the process as transparent as possible so you're clear about the fact that they're not on anyone's side.
They're also asking if you want legal advice so they can direct you to a service that can provide it if you want it.
They're also not being malicious when they ask if you're willing to attend; they're probably just attuned to your skepticism about the process and want to work out if you're actually going to attend or if they can forward the s 60I certificate to the other party and reallocate the mediation time to some other family in need.
Try and change your view about mediation being a 'risk'. It's not. It's actually a very good process if both parties are willing to participate for the purpose of reaching an outcome. If you go in there with a chip on your shoulder and in the mindset of everyone being against you, it will fail, but if you go in there open to negotiation and thinking of it as an opportunity to talk about any issues that you're having as well, you're probably going to find it far more favourable for your child.
Now, this is just for personal insight, more than anything else, but hopefully it helps you see the situation more objectively.
My husband requested mediation with his ex about a year ago because a lot issues were emerging shortly after orders were made, such as interference with the child's phone calls, threats for Court proceedings if he didn't sacrifice his plans during the child's time with him to accommodate the mother's plans, misuse of communication mediums, and what I have generously referred to as 'confusion' about interpretation of the orders around holiday time (read: obvious and deliberate manipulation of the orders to frustrate the child's time with her dad). It was causing all kind of issues, primarily the child being exposed to elevated conflict.
Despite my husband raising these as concerns and issues repeatedly with both the mother directly, and then her lawyer, the mother wanted an agenda before agreeing to attend mediation. He told the mediator what the issues were, but requested they be kept confidential because he suspected she would refuse to attend on grounds that she did not agree issues he was having were genuine issues that met her standards.
So, in the end, she refused to attend anyway, and the issues kept occurring. It culminated after many months into a domestic violence order filed by my husband, which resulted in changing the parenting orders to address the aforementioned issues anyway.
It would have been better if she'd just attended in the first place, rather than pretend the issues weren't issues and carry on with the same, destructive behaviour until desperate times called for desperate measures, and she ended up with an angry Magistrate telling her, literally, to pull her head in.
So, my suggestion is to attend with good intentions. Mediation is a positive process, intended to help not just the mother, but also you, as well.