There is a non-confrontational way to do this. Download the PDF, figure out what is making you uncomfortable (or hire a lawyer to review), and just send a list of concerns. Make them matter of fact, but not accusatory.

This is assertive. But it's not "confrontational." And if your employer withdraws the offer because of it, it's a huge red flag and you're lucky. But I've never seen an offer revoked for asking questions.

If you have more leverage, then you can be more "confrontational." You might want to mark up the agreement (or have a lawyer do it) and send back. That may seem a bit more forward, but you can certainly do it.

Please don't think you can't question what your employer puts in front of you. Maybe they won't revise the agreement for you, but it's worth trying if you have concerns.