I replied to your email, but I'll put it up again here (I get this type of question a lot)
If you don't want to use plugins, you'll have to make most of your 
items, magic, etc. programs (instead of using the Toolkit's items, 
special moves, etc).
For items, for example, I have an array of literal variables for each 
item name in the player's inventory (i.e. #item[x!]$, where x! is the 
item slot number).  Lets say I have a method that gets one of those 
names and puts it into the variable "item$".
I what I do is create a program for each item, and call it the same 
name as that item (i.e. Potion.prg).  Then I put a method in it that is 
run when the player uses an item, and call it #use_XXX, or something, 
where XXX is the item name.
Your battle/menu sytem needs to use the item in item$, so you need to 
include the program that corresponds to that item:
#item_program$=item$+".prg"
#include(item_program$)
If item$="Potion" this will include "Potion.prg"
Now you need to execute the method in that program:
#item_method$="#use_"+item$
#rpgcode(item_method$)
Again, if item$="Potion", this will be the same as #use_potion, and 
your potion method will run.
Spells work in a similar way.  Enemies too, except you'll just be 
loading variables in thier programs.
You can use the normal internal characters if you want because of the 
#getHP, etc. commands, but if you want them to have custom variables, 
you'll have to load them via programs as well.
Hope this helps!