Okay, I'm sorry I jumped on you. If you like the number you are currently using for the installer code and don't wish to learn a new one, then program in a completely new installer code, then create a master code consisting of your old installer code. You get to keep using the same number, except now it will be a master code.
I wasn't clear from your system description whether you have any auxiliary power supplies. If not, it sounds like you may be pushing the limit. The quick and easy way to get the auxiliary current draw is not to calculate it, but rather, to measure it. Set your meter on a current scale that will handle at least 2 amps. Disconnect everything from terminal 6, connect the positive meter lead to terminal 6 and the negative meter lead to all the wires you removed from terminal 6. Read the current: the panel is specified for a maximum of 750 ma aux power. Personally, I prefer not to push it to the limit.
You can get a rough idea by referring to spec sheets: 7 keypads at 40ma each, expansion modules at xx ma each, and so on. If you were seriously overloading the power supply,. it would let you know.
However, your batteries may be inadequate. Since you have smoke detectors, your system is supposed to operate for 24 hours on batteries, though I doubt the battery police will be knocking on your door. To calculate the standby time, take the measured current draw and add another 300 ma for the control panel itself, then divide that total into the total amp-hour rating of the batteries you are using. This isn't really the absolutely correct way to calculate this, but it will put you ballpark-close, and save me a lot of typing.
Finally, I'd suggest you get at least one 6160 keypad. Your system is big enough for an alpha keypad to be of value, and it's particularly useful for programming purposes.