1. Not really,. My statements about aliens apply to this universe only.
2. Sure. But science can prove a lot of things. Parallel universes may some day be among those things even if we never see them.
3. Aliens wouldn't be boring. Neither would rainbow farting unicorns. Neither exist. The math spelling that out is in this thread. Some people don't grasp it. Others grasp it but deny it because they want to smoke pot and ponder like the comment above describes. That's harmless I guess but math is math whether sober or stoned.