Honestly head first really is not a significant concern.
#1 hazard is drivers pulling out on the road into your lane and not being aware of the 27 mph you are going.
In this situation if your breaks do not stop you in time. You will want a sports cup and not a helmet. You will also want new front disk breaks and some times a front fork.
Solution: a loud horn and being aware the risk.
#2 is not using 2 hands for even a split second while doing any speed.
In this case your front tire twists and you get thrown. In this situation the first thing to break is the pinky toe and bone connected. Then your palm and next is your choice. Flip on back or face plant and slide it out.
Solution: front tire stablizers that mount to the deck and a good set of gloves
#3 is using the front break thinking it is the back break.
This will throw you face first over the handle bars. Most people put out their hand to break the fall and mess up their wrist for a few days.
Solution: a good set of gloves
The last problems are.. eatting bugs and trying to see at 27 mph.
Solution: yellow polarized glasses for night time and a day time option.
For the bugs. Free protien? Face mask or bandana work fine.
Unless your doing 40+ mph and care about life and teeth. Well a full helmet, neck brace, gloves, jacket, pants. Also getting tboned will suck. no flashing lights or horns can prepare a driver for a 40+mph moving body that is on the other side of cars. you are the drivers blank spot.