When it comes to determining how much healing to apply you could do both if you're not sure. A 'light heal' would probably be around 25%, regular heal around 50% and a heavy heal would be around 75% if you're going percentages. For the encounter rates I would play test your game a bunch of times and ask yourself how it 'feels'. Does it feel like you get into combat too much? If so, then increase the steps needed for an encounter to happen.
For balancing stats it's the same approach. You will end up playing your game much much more than anyone else if you're doing it right. I like to set one thing in stone and then balance the other around that. For example, decided the actors/classes stats curve and then don't change it much. If the enemies take too many hits to kill, you adjust the enemies hp and defense at that point. If you keep changing actor/class stats and ALSO enemy stats you will balance one fight and break the next.
Anyway keep up the good work.