NVX

id disable the bukkit plugins that are spewing stack traces everywhere first and go from there. Essentials is a terribly written plugin that conflicts with almost anything. It also looks like your server cant access the internet, or if it can, is having issues resolving hostnames. Id fix that too...

Your issues most likely stem from redalloy wire (any form) on the output of a timer, or any other clock. It will rape your bandwidth (I've seen over 5mbit per player in one machine that had a lot of it). Fix is to use vanilla dust where the redstone signal changes a lot, or put your timer right next to the frame motor with no cable between it. Say what you will about Elloraams coding abilities, but she dun goofed this one. :)

Bandwidth usage can vary from 'similar to vanilla' (there's lots of info on this, so I wont bother repeating) to multiple-megabits-per-second-per-user depending on what's been built. RP2 redalloy wire really uses a lot when attached to a continuously ticking clock. I've had one factory use up to 5mbit/s per player near it. Building with that in mind can save a lot of bandwidth. Ie, use vanilla dust instead of redalloy (even if insulated or jacketed!), or even better having timer outputs directly attached to the machine using it with no wire in-between. 20 timers next to 20 machines uses far less than 1 timer + 1 block of redalloy on the output.

You'll find timers use surprisingly little bandwidth, its the redalloy wire. Insulated, uninsulated, jacketed - it makes almost no difference. Bundled I believe uses slightly less, but I've not done much testing. Using vanilla redstone dust or having timers directly adjacent to the frame/machine with no wire in between uses the least bandwidth. A rather large factory on my server went from 5mbit/s per player to ~0.5mbit/s by removing all redalloy wire on timer outputs. It only uses bandwidth when it changes state, so slow timers, or signals from buttons/levers are fine to run over redalloy, just nothing that changes state fast. Hope this helps!