Provide a combat system consisting of basic defenses and curing. No offensive systems will be included in the ACP, though there may be some base code on top of which such things may be implemented by the users.
Make the system useable by a majority of Achaeans. This primarily means it should be easy to install and use. Scripts for other clients are encouraged, to help broaden the scope of the project. The project started on zMUD, of course, and is still supported today. Recently, a lot of code has been written for MUSHclient, though it remains unsupported (ironically, due to its complexity). Others have expressed interest in possibly providing free curing systems for other clients, also.
Teach others how to configure the scripts and develop their own scripts. The ACP should be a teaching tool for users of varying skill in scripting. Novice users may learn from the use of aliases and variables to track afflictions or defenses, while more advanced users may find ways to improve the failsafes.
Develop a community to support the project and keep it well maintained. Open source projects rely on people getting involved. I have been fortunate enough to have assistance from some great people on implementing, testing, and debugging parts of the system. The support of everyone involved has kept the project alive.

Increase execution speed. With each new script that I write, I learn new things and find new ways to apply my knowledge to making scripts faster and more efficient. The first module I wrote eventually became so slow that it simply crashed. The module prior to this latest one (XL) works for most situations, but it is still slow and sometimes misses opportunities. You'll find many optimizations in this new code (LE).
Increase the stability of the system. One thing I have learned about zMUD is that it has limitations. Executing a thousand triggers or firing a couple dozen alarms can wreak havoc on your system. There are ways to improve the stability of the scripts to prevent a majority of the problems seen in previous versions. Hopefully, no new instabilities are introduced in the process.
Increase flexibility and adaptability. From feedback I have received and in my own limited experience fighting in Achaea, it becomes obvious that a combat system should have some easy way to adapt to dynamically changing situations. You use different tactics when fighting one person or five, when fighting an Occultist or a Priest, when attempting to escape or trying to kill your target. You might want to heal clumsiness to make your next attack more effective, or you might want to sip mana over health to avoid a catharsis. The ACP won't adapt to these situations automatically, but it will be written in such a way as to make it easier for a skilled user to manipulate it.