This game heavily supports "cross-breeds" like mage/wizard or fighter/ranger... so no, definitely STR on a staff/INT on an axe/DEX on a staff etc. etc. is not something that needs 'fixing'... as there ain't anything broken.
Please point out when Dex on a staff would be remotely useful for anyone investing in Scoundrel skills, Marksman skills and magic skills.
Dodge is one (then there is Fast track, Stealth for starters with Rogue and First Aid, Tactical Retreat for Ranger), but I have a feeling this is going to be an argument of exceptions and excuses where we get back to the point of you saying what is the wrong way to play. I mean, you seem to be making the argument that damage based abilities are the only worthwhile thing to focus on in a build?
I'm sure that one point of dex is really going to matter.
Fast Track and Stealth are nice...and then you realize you have to switch weapons again for your backstab, thus costing AP. First Aid has limited applications in combat, you literally have to be right next to the fellow in question (and you can heal/buff through those effects anyway).
You're literally arguing with me that two skill lines - one of which revolves around ranged combat, the other sneaking and attacking with a dagger while laying down CC that also requires a dagger - would benefit from a staff with Dex despite 75% of those skill line's abilities being useless with anything other than the weapons they revolve around.
I can literally think of no reason why you'd use your staff as anything other than a sub-par stat stick, and then you realize that you also need Int to actually use the staff. Marksman and Scoundrel skill users already have to juggle between Dex, Speed and Perception, and now you want the poor buggers to juggle Intelligence as well? That's basically MAD taken to the most extreme point.
And you still miss my point that staves don't synergize with anything well. Can't be boosted without a specific reagent, can't be improved with ore, damage is subpar to other weapons of the same level, useless to Int users because they don't affect spells...