It would seem to me that proper interpretation is self-rewarding, especially in the long run.
But I agree with BenJoss that if a character proposes doing something specific that would logically lead to discovery, there is often no need for a spot hidden roll at all. A Spot Hidden roll might gain the clue, "The painting appears to be recently moved.", but if the character actually proposes looking behind the painting he doesn't need to make a Spot Hidden roll to see what is behind it (whether beneficial or Sanity destroying).
For me, one problem I run into is the problem of 'trains of thought'. As players discover things and begin to speculate on them, they generally want to know how what they've discovered or what they are speculating on relates to things that they know as a result of their academic background. If a character finds a clue as a result of Library Use, that clue might logically lead to all sorts of associations. For example, if you find in the library that the peculiar brachiform runes on the green soapstone stele you found resemble writing that has been associated with the lost continent of Mu, this often causes the player to call out Archaeology to see to see if you can recall details about research or expeditions into Mu. That in turn provokes a potentially veritable torrent of information, most notably the name Harold Copeland, which might provoke calls for History tells and Know rolls and so forth. For example, not only might a informed Archaeologist recall the specific expeditions and published works, but they might recall that Dr. Copeland is still alive and confined to a Arkham Sanitarium. But what I hate doing is turning this in to a really long series of skill, Luck, Idea, and Know rolls to try to figure out what the character already knows, even in situations where it is reasonably that the character might know something, because this tends to become somewhat boring and rather mechanical and leads to players calling out as many skills as they can think of in hoping of getting check marks. I'm torn between being fair and simulating the knowledge a PC has that seems to be the implication of the skill system most of the time and just saying what the character remembers with no tests to avoid all the rolling and fishing expeditions.