Airways and flight plans
 

Can you take-off from an airport that has an airway going right over it and instead of flying to a VOR after take-off, just join the airway right there? If so, is there a certain distance that you have to get established on that airway?

In my experience (pilot), I have never been required to physically overfly a VOR station when joining an airway commencing at a VOR located at my departure airport. Normally I've been given either a SID (which usually intercepts an outbound radial eventually), or a visual departure. In Australia, when on a visual departure there is a requirement to intercept the cleared route within 5 miles, unless ATC prescribe otherwise. I'm not sure of the requirements elsewhere.

You should be able to get a clearance along the lines of "cleared to join CAS on track xxx (waypoint), climbing yyy".

ap