Server Crash Report - What To Look For?

Hi there, my server's been having a few crashes recently and I'm trying to investigate why.
I've got a crash report here but I don't know what to look for that will tell me the issue?

Could you please take a look at this crash report and tell me the issue.
And could you please tell me what to look for in the report for the future? Thanks.
http://pastebin.com/fN3QFRJK

 

#1 - You are running a bleeding edge developer version (Craftbukkit 1.7.10)
#2 - You are running a crap-ton (tm) of plugins

With that many plugins, you should consider not trying to push them on the latest builds before the plugins have had time to catch up.

The error is complaining about a tick on an arrow entity so I don't know what to say about that...nothing obvious to me.

 

3104 fixes something to do with EntityDamageEvent.

 

Removed some offtopic posts. Definitely check out the latest dev build.