I understand the level modeling concept - nothing wrong with that but it does have limitations. A good way to use it is to have for each type of activity one level. But how do you handle the case where you have basically the same activity but somehow more intense? For example suck nipples for 1 minute is different from doing it for 20 minutes. One way to do it is having e.g. role play mild, medium and extreme versions. A solution that works for a single or few categories but does not scale.
One clean option to get that would be to model intensity as an action attribute acting as an increment to the computed intensity. For reasons of not accidently disabling actions one might limit the max sum to 9.
On way to work around it currently would be to have an absolut level category e.g. named "level 7 (internal use must be enabled)". This way if you have an activity that computes to level 6 you can elevate it to level 7. Of course it starts falling down when users adjust the levels downward.
I'm not sure it is worth it, but I could imagine there is often the case when there is a tamer version and a harder one of the same action. One would be o.k. at a lower level, some other may require a higher level.