[Admins]

I can possibly add yours. There will be more documentation for v3.1 scripting engine once it is released.

About clientside-system: a hitpoint-system should be secure and easy to use. On serverside you can build a database of objects which you can use to influence the hitpoint system, e.g. weapon strength and armour. If you don't script bad stuff into the hp functions then speed shouldn't be a problem at all. With 100 players playing on Graal Kingdoms the HP system uses less than 1% of the cpu time, although it's doing quite complicated hitpoint calculations.
On most Graal servers the clientside scripts are a much bigger speed problem (I have seen servers with quite slow clientside weapon scripts which then lag the players while the npcserver is bored)