I found an answer to my first question in the Wiki,
Oneshot 125
"Same as PWMSync, the CC3D/Atom need a
one wire RcInput like PPM(pin8), SBUS, DSM, SRXL...
Old PPM input (pin1) DO NOT ALLOW PWMSync
See CC3D hardware page for more details".
So I guess I will have to upgrade my ER9X Transmitter and receiver, XJT module that will do PPM or S-bus or might be a good excuse to get a Taranis QX7.
Still having problems with, Always Stabilized When Armed, I have no stabilization when throttle is at zero, only when throttle is raised a bit. Funny it worked great with the SimonK esc's but not the Racerstar esc's with Blheli_s. I can also arm the quad using a switch, in any flight mode, which you are not suppose to be able to do I thought.
Could running the Blheli_s esc's at 490 Rapid ESC setting be causing problems?
I would like to get Always Stabilized when Armed to work properly if possible but kind of stuck at the moment.
Thanks again, Robert.