Of course this makes sense . Perhaps the general question is how the XP system can help to encourage players to develop a wider range of skills for their PCs, in this case including RRs, instead of focusing only on e.g. combat.
I don't agree here. I think it is the GMs responsibility to do this. For example: If the group plans on going on a long expedition into the jungles of Y'thrain, don't leave it up to one or two members of the group to get jungle survival skills. Everyone should have some skill in survival so they at thee very least, aren't negative modifiers to the group survival skill checks. (Yes, this is a problem for level-based games which require you go up a level in order to gain skills - which is why I prefer levelless systems.)
I mentioned it on another XP thread, but I don't award XP at all when running HARP/RM/or any other level-based system. I level everyone up prior to the beginning of the 4Th session. For exceptional game-play, cool ideas, and the like I give in-game bonuses, such as bonus Fate Points (or whatever is used for that game) or even temporary bonuses to a group of actions for the rest of the session or the next encounter, whatever. That is all in addition to the immediate situational bonuses they get for having a good idea on how to deal with the problem at hand.
Of course, another way to do it is sort of adopt the Earthdawn method only in Development Points. Award development points instead of xp and when they reach a certain number of DPs they are the next level. In this case I would say that you should be using a set number of DPs, not have them dependant upon the individuals attributes. You would also have to deal with the whole max # of ranks / level situation, but since that number goes up very quickly (by 10Th level it's 33 max skill ranks in a single skill) so maybe that isn't a big deal once they get to a decent level. This method would allow them the option to learn new skills as they need them. Using the jungle example: the group finds itself in the jungle (not planned) so as they adventure they they will have the opportunity to gain skill ranks in jungle survival without having to gain a level, and thus show their growing familiarity with their surroundings. In some cases, I would think it totally appropriate for the GM to require the players to purchase some ranks in particular skills.