That's good to hear.
But what you're describing sounds like an awful lot figuring out. Not only that, it still relies on the abilities being listed in the enemy's stat sheet. Meaning they have to use that rating thing. The rating system only makes them more likely to do that thing. There is still tiny random chance that they will do something else even at the highest rating disparity.
This largely depends on what engine you're using. In MV and I think VXAce at least, you can set up essentially "checks" for whether or not to use a specific skill. I've done this in MV pretty heavily. I have basic wolves that check "If has state Burn L1, L2, L3, L4, use "Escape" with Priority 1". This results in the skill never being used... unless they happen to have "Burn" on them. You just click the "Condition" section of each skill you give the enemy and there's a wide array of options to choose from... including switches.
Yep, that's right, you could have the players do something in your game... it flips a switch... that, say... makes the boss use a weaker version of an attack they would have normally... as a reward for completing some kind of quest... or using some kind of Key Item... And then, so long as that switch is flipped, that action will be on their Skill Table.
There are actually a ton of options in there and interesting things you can do.
Then there's targeting. I guess you're doing this with eventing and states somehow? Because just the simple act of making a healer enemy that heals the lowest health ally is a brainbuster for me. I'd rather just use my plugin that just tells him to do exactly that with a single line of text, rather than jump through a bunch of hoops re-inventing RPG Maker with a bunch of events and states.
Yeah, this is definitely a problem. I did what
@Wavelength suggested to get my "heal the boss" enemies to work properly. They each have a Target Rate of 0% and their skill is set to "1 Ally". So, they never target themselves or each other and since their Target Rate is so low, they simply target the boss. But, they're designed to heal absolutely every single turn and do nothing else. If I wanted them to heal only at certain amounts of HP... I'd have a lot harder time doing it without a script or a plugin. I mean, it's doable... you could do it via Troop Commands, I think. Or creative use of the skills... But, it would probably require a lot of work that you just don't have to do with a script or a plugin.
You can do a lot with the basic engine, if you just get pretty creative in how it's used. I've accomplished a lot with very few plugins. I think all I'm really using is like... a Quest Journal (because I didn't want to muck about trying to event one and use Key Items to tell you if you completed it or not)… A "shop menu" thing that fixes shops so that they show more than just the benefits to "Attack" and "Defense" and actually show other stats... other features... elements of equipment... etcetera... a "status menu" thing in order to show off the same amount of stats to the players as the default status menu is kind of... bare bones... and a "party system" menu in order to keep a character in the party at all times and always in the same slot (a la Chrono from Chrono Trigger), since that would've been a nightmare to try to event. I simply haven't needed to script or plugin anything combat related. Heck, I accomplish a lot of interesting mechanics just by playing around with damage formulas and "Force Action" type effects from enemies. I even figured out a way to make enemies react when hit with certain elements.
You just gotta play with the engine a little bit. I tend to only resort to scripts/plugins when the engine doesn't do something I need it to do... or getting it to do that would take a lot of time eventing to accomplish.