Checkout interfaces

I'd like to have more control over the contents for each checkout step.

Right now I'd like to add the payment method notes to the checkout step to warn people beforehand about our conditions with each method. The problem is that the entire options interface is generated and no extra information is provided. Is this done by design, or something that needs refinement? I'd like it to be able to either use a hook or template to change the contents.

What do I do in the meantime? Remove the payment check and add my own?