1. Very good point, but still not an excuse for idiotic behavior.
2. Incredibly true, but still not an excuse for idiotic behavior.
3. Exactly the reason why one shouldn't go out looking for trouble.
Based on what SSB posted (trusting his summary at this point as I haven't read the doc yet). The defendant and his friend purposely armed themselves and went looking for the guy who caused the initial issue. Initial aggressor had withdrawn from the scene and AFAWK was not an immediate threat. 2 armed dudes show up and initiate contact with the aggressor who had withdrawn from the situation and now want to claim they were defending themselves. There is probably a decent case to be made that the only person actually defending himself in this scenario is the guy who left the scene and was later set upon by 2 armed dudes.
Have no clue on the technicalities of jury instruction, but if I'm on that jury there would need to be some mitigating circumstances to justify self defense, no mater how broadly the castle doctrine is written. They didn't happen upon the guy, they guy didn't come looking for them... they armed themselves and went looking for a guy they had a fight with. Not a good idea no matter how drunk or how unPC it is to call the police.