My wife and I are talking about polyamory, but have different ideas of how we'd like to date

My wife and I have gone back and forth for awhile and have agreed to try being poly/open. However, I don't have the time to explore much more then casual hook ups. She seems interested in more serious emotional experiences and is offended that I just want sex from other people. She's also got a lot of body issues that she uses as reasons for her not making the first move. How can we help each other to find some middle ground here?

If you two keep going back and forth, make sure that this is really what you two want to do and that you’re ready for it. Consider reading a book about polyamory, like More Than Two or The Ethical Slut, together, and talking about it. Talk together about best-case and worst-case scenarios. Ask questions. Be open. The fact that this continues to be a contentious subject between you two is a bit of a red flag.

You two can have different styles of dating - there’s this weird obsession with rigid score-counting ‘equality’ when previously mono couples ‘open’ their relationship, and I’d encourage you to let go of that. You can have lots of flings, one-night-stands, casual sex, etc. She can have more emotional connections, long-term dating relationships, etc. That doesn’t really change or threaten anything between you two, unless you decide that it does. 

Talk to her about why that offends her. Is she feeling, perhaps, like your preference for “just sex” means that your motives for opening the relationship are that you’re no longer sexually attracted to her? That can feel vulnerable and threatening. Maybe she’s framed it as “if being polyamorous is about who he is as a person, about his capacity to love and desire to connect with more people, then that makes sense. If he just wants to sleep with other people who aren’t me, then that bothers me.” You two need to figure out how you’re both framing this and do some work on the assumptions and fears behind that framing.

Anxiety and insecurity around body image can be pretty serious, especially for women. She is not “using these as reasons,” they are her reasons. If she is feeling held back in her life by them, I strongly encourage therapy focused on radical self acceptance and healing from toxic ideas about our bodies. You can find some resources here. Recognize that and have compassion. She doesn’t need to “make the first move” or be more sexually outgoing for this to work; so don’t pressure her to do that. Again, if you two let go of this need for things to look identical on both sides, you don’t need to push her to date a certain way just to swing permission for yourself to do that.