Brent, good question. As a good rule of thumb, you want to choose your screw based on the material you are screwing into, not the material you drilled the Pocket-Hole into. With use of ¾” plywood you were correct in your screw selection with the 1 ¼” coarse screw. This screw is only available in the #8 style since it is a coarse thread. When you are going from the plywood into the oak face frame you are once again correct in your screw selection. If you are having a lot of problems with splitting in this situation you can switch to the pan head screws which would be a #6. (for everyone else's information, these numbers reference the diameter of the screw's shank) This would be a little easier to drive due to the smaller shank but will not give you quite the same holding power that the washer head screw offers. Also you will have to be careful with the pan head screws. With its smaller head it can try to pull into your pocket hole a bit so make sure you have your clutch set correctly.
From what you have posted it sounds like you really have a good grasp on screw selection and should have no problems using pocket holes in your projects! Good luck, and good woodworking!