flaky starter switch contributing to poor running?

[Livolsi, Stephane]

Still having poor running problem on my 88 5ktqa.  - sounds like a miss
at low rpm and under acceleration, but does ok at higher speeds/rpm.
Doesn't make full boost though, only 1.1
 
This morning the car wouldn't start (at first) when I turned the key.
dash lights came on and dimmed a bit as usual when turned to start, but
no whirr of the starter motor.  Took the key out, turned it around,
wiggled a bit while turning and it started.  Me suspects a flaky starter
switch, as happened in my 86 5ktq.
 
Anyone have insight that would indicate this might cause the rough
running?
Others have suggested checking voltages at certain points in the engine
bay, which I am doing this weekend (haven't had time yet)
 
TIA
 
Stephane