msimon, I would say - do whatever feels good and doesn't hurt. Take it slowly. Sex didn't cause me any problems while my fissure was active, except that I felt so yucky down there I couldn't get interested. If I made the effort, it was fine.
Orgasm didn't hurt or have repercussions.
Everyone is different, so be careful. And try to have fun!
I haven't had any sex since about 7 months before the baby was born and then had this happened so I haven't had anything for around 9-10 months. No other sort of play either as I'm not interested. When/if this heals I will then have to deal with the episiotomy pain and scarring so I'm just kind of ignoring that side of me at the moment.