Hi newcomer and welcome to the Tom's hardware forum.
1- The RAM modules are different speed, in that case all the RAM only can run to the lowest speed (667MHz) and don't care the slot where u install the RAM module.
2- Yeah, the mobo only can handle one timing specifications for the RAM.
3- U need change this specs: CL, tRCD, tRP and tRAS. Set the rest in auto and the voltage to 1.8V.