Sure. The one time you use it for self defense, the police come, investigate, impound the gun (temporarily), the possession goes on record which can then be accessed by the feds along with your medical marijuana card.
Yes.
Using marijuana and possessing a firearm is illegal under federal law. What part of that aren't you getting?
Look, you can go the rest of your life using marijuana and owning firearms and maybe nothing will ever come of it. But Murphy's Law says whatever can go wrong will go wrong.
We've explained the risks. It's entirely up to you now.

