"Star Trek": Black Holes and Plot Holes

Ok, I watched the new Star Trek movie twice more over vacation, and I still really like it. The first 10 minutes are absolutely sensational.

Unfortunately, after those first 10 minutes, I am left with many, many questions that have only multiplied after repeated viewings. I would appreciate fellow dork assistance. If there are answers to these seeming plot holes, please enlighten me. If you have other questions, pile on.

Mild spoiler alert!

1. Why does Nero's mining vessel have so many weapons on it?

2. What does Nero do for the 20+ years between destroying the Kelvin and attacking the Klingons/Star Fleet?

3. Why does he attack the Klingons?

4. What is the "lightning strike in space"? Is it the ship appearing through the event horizon/time warp, or is it destroying ships with their advanced weapons? Because in the Kelvin's case, it seems to be the former, but in the second Nero spotting (attack on Klingon warbirds), it seems to be the latter.

5. The biggest one: How does he know the exact time that (old) Spock will reappear through the rip in space? He's right there waiting for him, even though theoretically it could be any time, right?

6. Why doesn't he go back to Romulus and warn them that their planet's going to be destroyed in 100 years instead of being such a colossal prick about something that hasn't actually happened yet? Granted, he's not all that rational, since he blames Spock for little-to-no reason in the first place.

7. If one drop of red matter is enough to destroy an entire planet, why is Spock traveling around with a giant ball of it?