Situation: if the player passes a speechcraft skill check, I would like to reward the player with an increase in their speechcraft skill as though it were being used. There are five tiers of difficulty (very easy, easy, average, hard, and very hard). I would like to reward more skill use the higher the difficulty of the persuasion check.

I have a few questions:

1. OBSE has a number of commands (such as IncrementPlayerSkillUse) that do as I'd like, but if the gained exp is over one skill boost (i.e., player gains enough skill exp to go up more than one skill point), it does not register correctly, and the skill increases once but the experience is over the maximum, meaning that the next uses of the skill will trigger immediate advancement.

2. I would like opinions on how difficult the checks should be and how much skill use should be rewarded.

As is for difficulty checks:

Very easy = 10 skill, 1 skill use
Easy = 25 skill, 3 skill uses
Average = 40 skill, 5 skill uses
Hard = 65 skill, 8 skill uses
Very hard = 80 skill, 10 skill uses

For reference, "skill uses" number is equivalent to playing a round of the persuasion minigame that many times.