The timing is listed on the emission decal, and it's probably 9 degrees, so if you're reading 10 it's okay. On the M103 I find using a dial back timing light is the best way to check timing. Dial the 0/T mark back to the pointer and read the dial on the light. The pointer for timing and the TDC sensor are not along the same radial line. There is a radial dowel pin on the balancer that signals TDC as it passes the magnetic pickup.
Your data indicates that the EGR valve vacuum diaphragm is opening and closing the valve, but the valve could be leaking. Figure out a way to check that the valve itself is not leaking when it's closed.
A quick test is to apply vacuum to open the valve at idle. Degradation of idle quality and vacuum indicates that the valve is functioning, but it still might be leaky. When the vavle opens at idle the change should be very noticeable. If not, good chance the valve is leaking, which would result in poor manifold vacuum/idle quality and sluggish acceleration. You've got the classic symptoms of a stuck open or leaking EGR valve.
Idle vacuum at 700 in neutral should be about 15-16". Free-revving at 2000 it should be about 20".