What if i overflows: either an overflow error and a crash, or it resets to 0 or a large negative number if it's a signed int. Whichever way that...
You are on online-mode=true aren't you?
Linux-based OS'es can be faster, but if you've never used them you'd be much better off sticking with Windows.
Oh and leave server-ip= blank in server.properties
put online-mode=true in server.properties
PLEASE read about SQL injection before you deploy that code!
To rollback TNT amd other griefing, you need a logging plugin such as BigBrother, HawkEye or LogBlock, although I'm not sure which ones are still...
What about Chunkster?
For 15 people, you'll need more than 1GB RAM (usual recommendation is 100MB/person, more for lots of plugins).
Have you port forwarded?
-Xincgc will switch on agressive garbage collection, reducing RAM usage and helping to stem memory leaks, but will require more CPU
Nope. You can use it to store permissions, but you don't need it as such.
If your server is stopping when you close the remote connection, you need to prefix the start command with "screen" to run it in GNU Screen,...
While running your server, go to canyouseeme.org, and check port 25565.
No you don't. As TnT has repeatedly told you, offline mode is a very bad thing.
Anything after the command name itself is passed to the plugin as arguments, I'm afraid I don't know any more than that.
Although it does tell you something about its speed when they have to compile their code base to C++ and the result is twice as fast
You say you "don't think to change offline mode", and I have no idea what you mean, but you should put it on. The bukkit community doesn't tend to...
Here comes the holy war...
What CraftBukkit build are you running?
Separate names with a comma.