Too many plugins.
If you're looking to host around 10-20 people, and you don't have a proper server setup, don't overload it with so many plugins. Tekkit already has a large load with the mods that it carries around, putting [THIRTY-SIX] Extra, unnecessary plugins will only add to the burden.
Seriously, cool it with the plugins.
As for your choice for some of the plugins, just no.
Stop.
You don't need that many redundant plugins.
1. Dynmap can be very resource demanding. Use it sparingly
2. Chestshop is your friend. You can replace 6 of your economy plugins with this very simple one
3. Creeperheal will also negate a fair amount of plugins, as it prevents griefing with tnt, fire, as well as natural griefing (creepers, fire, ghasts)
4. As much as I hate Essentials, it has many of the functionality that you're using other plugins for. Get rid of either, and you'll notice a difference.
5. On a well-managed server, you should be running no more than 12 plugins, 80% CPU, 75% total RAM, and 3% of your network utilization.
Also, on another note, if you want to tweak your server a bit more...
[ONLY FOR ADVANCED WINDOWS USERS]
1. Disable all services not related to crucial processes.
2. stop explorer.exe
3. Only have core services, server.bat, and task manager running
Note: If you stop explorer.exe, your WHOLE desktop will be gone. Your desktop uses ~1% cpu, and maybe some Ram, but that, along with many other things, can add about 10% more leeway for your server, when it's needed. Otherwise, it will keep your system cooler. Whenever you need your desktop again, just open task manager, and add new task, then type in explorer.exe
But specifically for you, get rid of some plugins. That's your main concern