I received basically the same things that happened to you, Earther. I'm on xbox one. One time, both my friend and I had Destiny freeze on us at the same time. We both activated firefly. I had a hand cannon and he had a sniper. The other guy was still in the game after we had to shutdown Destiny. He said the game just slowed down and almost froze but after a minute continued as normal. My Stormcaller is not fun to use because of how much the storm grenade drops the frame rate. I hope everything is solved in the next patch or the following one. I miss using firefly and my Warlock.