Hi w0nwa,
1. Please list specific planes and which issue they have. Double check your sound settings under settings menu -> sound. Some third party aircraft override these settings to do what they want. :)
2. If you want to start on the ramp instead of the runway, go to settings -> operation & warnings & check "start each flight on ramp." This is a global setting for every flight though.
Autopilot is set up individually for each plane so they will not all have the same control capabilities. If it looks like it should have alt control (a button or something) and is a default plane, please file a bug here and be as specific as possible with your explanation of what you expected vs. what was wrong.
Manipulating trim from within the cockpit could be the same issue if the designer didn't make the trim controls manipulable.