Though the creation of interactions is already quite intuitive and fun, there still are bits I have an issue with.
1. The position of the Gizmos for hands and feet.
Trying to place feet and hooves on the ground or placing hands on surfaces ends up for me at least in a perpetual struggle of switching between rotation and seeing the body part getting submerged and translation to see that the angle is still not quite right. This could be resolved by placing the point of rotation right at the palm of the hand and sole of the foot.
2. The Work needed to actually get a hand or foot to where I want it to be.
Moving a limb to the intended position takes an unreasonable amount of tweaking.
Move the joint > change the camera position > rotate the camera > repeat.
So what I suggest is adding a "Position (Q)" tool that works similar to the way a new character is added. Klick the tool or use the shortcut, then click the surface you want the Gizmo positioned at. This could cut down time to position foot on the floor from the better part of a minute to two clicks
3. Having to move the female to move the male.
One major hassle for me is creating riding scenarios as you are forced to add the male to the female, then change the control and distance in the thrusting menu and then move both to the wanted position based on the female hip. This could be done a lot more elegant by just being able to add females to males. Place the male, let him sit in the lounge chair and when happy with the result add the female.
For versions a good bit further down the line it might also be a good idea to have a look into CAD software and how they handle relations, especially concerning cylinders. It might allow to move away from the discrete "this rod goes into one of those holes" to a more open "This is the relation between these two parts".