First issue: when your juiced and the game pauses while the host migrates, my skills reset and i start without juice even if i just used my juice right before the migration started. Second issue: In the spunky cola arena (and other arena's i have noticed) when you spawn Buzzers they often run into the walls or sometimes go right through them, and many times they are invisible when you take damage from them. Not very important issues i suppose, but issues nonetheless.
About the buzzers being invisible, are you sure you weren't just looking away from them when you were hit? The camera allows you see very little you're directly facing due to it being so close to your pro and buzzers are pretty small: about the size of your pro's head. Combined with their odd flight patterns and the fact that more often than not they attack from above...are you sure you weren't looking away when they hit you?