You could just completely remove the front sway bar also. It'll help cut down on the understeer but thats a pretty serious mod. That will significantly change the handling of the car and you may find yourself in a tricky situation at high speed. EG: My car feels a little twitchy on the highway sometimes.
I suspect that after the suspension install the bolts just worked their way loose and you didn't catch it until it came off. The nuts on the end links are supposed to be a one time use nut. The Honda ones have a slight oval shape to them IIRC that helps them lock into place when you torque them down. I have reused them before but I highly suggest new ones, they are super cheap, and as always check all your bolts after an install especially after some mileage.