1. An attempt to take off under any kind of roof will result in the pawn injuring their head slightly.
2. An attempt to land on a roof will result in the roof collapsing under the pawns weight or, in case of a mountain roof, not launch at all.
3. Takeoff with regular chemfuel should have a very small chance to start a fire at the point of takeoff. For balance.
4. The range of the jetpack should be affected by the total mass carried by the pawn. If nothing but the jetpack is equipped, the pawn should be able to travel further on the same amount of fuel.
5. Landing on a living thing should deal damage to it, you're goombastomping it after all. Maybe a small chance for an instant kill.
Also 6. slightly arch the trajoctory to give give it the illusion of height.