This is not easy for a beginner, you will spend hours reading to sort it out (unless you wrote the firmware
) so sit back and glean a little each day.
IMHO er9x would be best, it has been around for awhile with lots of documentation available. Open9x is rather "new", get some experience with er9x first.
If you intend using eePe to program your Tx you will find some templates within the program to assist. Simple 4 channel, very simple and easy, for a 4ch plane a good place to start.
6ch heli is also available but there is nothing simple about 6ch helis, be very careful and as Hal9000 has already stated learn all about throttle safety switch/throttle cut. That in itself will save you pain and anguish as well as instructing you on the use of er9x. The eePe program has a simulator function that you can test your settings, learning to use that and translating to your model will also save some pain and anguish.
There is a lot of useful info on the 9x forums, you just have to spend the time, "Westy" does a very good tutorial for setting up 6ch helis.
Once you have some confidence in er9x you will be amazed what you can do.
Your suggestion about adding up elevator for launch, IMHO should not be related to throttle position. You could find yourself not wanting this during normal flight so I would suggest that you have this applied by a simple switch setting, so once you have launched you can cancel the up elevator setting by a "flick of the switch"
. The beauty of er9x is that you can assign any requirement to any switch, just because it is known as the "gear" switch doesn't mean it just does gears it could "apply up elevator" or it could ""activate bomb drop"
Good luck, Dennis
PS down load some templates from the 9x forums and have a play, best way to learn & understand.