Some questions:
1. Is the entire wall of the first floor cinder block?

2. By "framing," do you mean the exterior walls of the second floor?
If so, that's a traditional construction method.

3. I'm afraid I got a little lost on 'lateral support for the side
frame.' I think your concern is keeping the exterior walls from bowing
out when the rafters are put on top of the walls. With only 2 feet of
fall in 11 feet, I would have similar concerns. I would rethink a roof
pitch that shallow, particularly if you are going to use an asphalt
shingle roof system. If not, collar ties will be a must.
Additionally, I think a 4x8 ridge is a bit of overkill, but that's just
me.

4. Why only 6-foot walls? The cost of raising your ceiling 2 feet
should be minimal, and it's better to have it and not need it than the
other way around.

5. Why a clear span beam on the first floor? By putting one post in
the middle, you could use a doubled 2x10 and still have more strength
than you need. That would save you a bit of money.
I hope I didn't muddy the waters too much

-Phil Crow