That goes against the meaning of “favourites”.
Added to v.55 
Idea Oh god, more keys
It all depends if that weak beam kills any enemies or not. If it does, I see a multi-kill is awarded (as it should). The multi-kill bonus doesn’t care what weapon is used, it just checks to see if successive kills are within 1 second of each other.
It does count. Lightning that hits ANY target (regardless of whether it takes damage) counts as a hit. You need to miss completely out into space in order to lose the medal.
You can end session before you damage your first enemy on each wave without repercussions. There is a warning message on the pause screen that lets you know if it’s ‘safe’ to disconnect.
Not really possible, no.
I could. The danger of this is that the first time you play this mission type ever, it’s not guaranteed that you’ll see the unique boss. You might see a boss you’ve already seen in other mission types before, and hence lose interest 