So, just to be clear, we're certainly aware that the loot system in Raid Finder needs to be smarter, as there's currently not a way for the system to determine loot eligibility based on talent specialization or class. To use the OP's example, if a Strength weapon drops and a hunter rolls on it, the system says "Yep, a DPS player is rolling on it. Okie dokie. Here's your +100." (We should really find ways for the game to say "okie dokie" in your chat log.)
This obviously needs to change and we're in the middle of discussing potential short-term solutions, as a more long-term solution will require programming new tech into the system which will account for class/spec.
We only ask that you keep in mind patch 4.3 is our first implementation of Raid Finder and the "Need Plus" system. The design is quite complicated and requires further iteration to make loot distribution more intelligent.
We recognize the issue with duplicate drops being won by the same person as well. This is something we need to fix.