Yes, of course a groom's opinion counts. One thing that has really annoyed me, has been people have kept telling my fiance that it's my day not his, he just has to turn up! I know they're joking, but also they're kind of not!
I'm doing the bulk of work for it, as we're doing a lot of DIY, and I'm more crafty, but I've really enjoyed discussing all aspects with him, and I've not made any final decisions without discussing it with him first.
Even my bridesmaids - I knew who I wanted, and there are 6 of them, so I discussed it with him to be sure he was happy with that number and the additional cost. There was actually a 7th candidate, but we agreed to ask her to do a reading instead, and he's doing the same with one of his friend's who isn't going to be an usher.
I would definitely have a chat with her. It's so easy to get swept up in the whole glow of booking things, but your wedding day is about the both of you, and your fiancee is lucky to have a chap who wants to get involved!
Depending on what you have left to book, why don't you suggest going to wedding fairs with her? She might love the fact that you want to go along! My fiance has also done a great job scouring Facebook marketplace for things to buy for our wedding, and sending me links. Maybe you could do this (if you haven't already)? That way, she will know that you want to have a say too.
Regarding her ex's parents, I too would find that really strange if my fiance wanted his ex's folks there. I guess it makes more sense if she see's them regularly, and they are her kid's grandparents, but couldn't they be invited as an evening guest instead?
Definitely have a chat with her, and sooner rather than later before she get s too much else booked!
Good luck! x