Alright, I got the whole combo system working for the player. I'll probably release version 2.74 soon for people to play around with and get ideas. You'll have to do a slight bit of scripting in the config section since the app won't be finished, but that's okay.
Here's the full list of features:
1. Define each combo separately in the config. You get to chose which weapons/items/skills/enemies use each combo
2. Each combo is made up of many 'actions'.
3. Each action has a core method called 'use' which is where you can tell the character using the combo to perform attacks, skills, items, defend, and even manually change the character's hp, sp, etc.
4. Each action allows you to define a simple move route consisting of steps, jumps, and turns.
5. Each action has a defined length, and a set of frames where the 'use' method will be called, meaning that you can time exactly the frame in the combo that the attack, skill, or whatever gets used, and it can be used multiple times in each action
6. Each action allows you to define a sprite (with custom frame numbers) and an animation centered on the player. This could be used to add audio and visual cues for the timing of combos, or just to add flair.
7. Each action allows you to define multiple start and end conditions, allowing you to end combos based on a variety of variables, and to require special situations to perform certain combos (full hp, for example).
8. Each action allows you to define the logic for connecting actions in the combo. This includes the timing of user input, character stat requirements, etc. Each action can branch off into multiple other possible actions, allowing for combos that start the same way, but end differently based on game conditions or user input.
phew, that's it. Lots of features there, I doubt any of you are going to feel limited by it's capabilities