While I understand what you're asking, Eegxeta, on the three skills that you mentioned, Sense Motive, Diplomacy, and Knowledge, there are other skills that cover the same types of deal for two of them.
Diplomacy is covered by the persuade skill, overall charisma, as well as gather information skill.
Knowledge is covered by the Lore skill.
Sense motive can be covered by bluff, but we tend to be careful because it can be easily abused into metagaming and telepathy- which is not allowed in Layonara.
I understand why you're asking for these things, but there is a lot of rp in the game that is simply rp and without rolls. Sure, there are times when rolls determine some things, but there are others that don't want to see dice rolls go up every time anything happens because it takes away from the immersion of the game somewhat.
Thanks for the suggestions, but as I said above, there are ways to cover those already in game.
Sometimes to be diplomatic, you simply have to learn to be diplomatic.