At some point I had a houserule of spell like abilities requiring the use of somatic and verbal components as normal. The fluff was that the components were simpler in nature but still necessary. The reason for this was that I wanted to stop outsiders shenanigans with hiding and spamming spell likes without making a sound. I remember finding outsiders too powerful in 3.5 especially compared to other monsters in the Core (except dragons), perhaps because they were a bit too low on the hd department in 3.0 the designers went the other way just a tad too much in 3.5.
I didn't hear complaints about this in pathfinder so maybe there is no need for this change or the fact they allowed weapons to ignore DR's acted as a indirect nerf to ousiders.
In any case the basic question is how would the game change if spell like abilities required somatic and verbal components?