For those flight modes (head (headless?) position and flight plan) you need GPS flight modes. For that you need INS13. INS13 needs GPS and mag for all flight modes, even for flight modes that you would think do not need it.
It sounds like you have alarms. In particular, INS13 won't arm until:
- you have GPS and mag installed correctly, configured correctly, and running correctly
- you have set home location
- mag is calibrated and green
- GPS has enough satellites to be green
- there are some flight modes it will not arm in, you must arm in other modes and switch to these
- there may be others I have forgotten...
You say that your mag is red. That is at least one thing that will keep it from arming and flying.
Atti and Stab turn green after everything else is correct.
When Atti and Stab turn green you can arm.
You must also twist and carefully route your high current motor power wires (battery to connector, connector to PDB, PDB to ESC, ESC to motor) to avoid mag problems that only happen when motors are running with flight load (with props on). Also, some PDB are not mag friendly.