Could RP XP be given a base value that grows larger with each bonus up to a limit that sticks with the character? That way, RPing to a reasonable level is actually an option, and LEs can be boosted by RP rather than a proclamation that you won't do anything until you hit at least 55 again?
RP EXP is only fine at specific levels. Early levels like 10-25 and late levels like 55-60. However between those points you're getting a negligible amount of TNL on a 2 hour cooldown which can be wasteful when you can probably get 1-3 whole levels off a single battle in the level 30 range.
The TNL should keep most of it's oomph while it slowly dies down to the baseline 10% until level 55. If I'm level 50 I'd probably like to get closer to 25% TNL, and at 40 I'd probably want 70% of TNL, just better than what it is now.