It’s the VOTERS who choose the Nominee by voting for their choice.
As for “airtime”, it’s the media that makes that determination, not the Party.
The Republican Party leaders HATE Trump; but the media was fascinated by a billionaire bigot running for President, and they gave him two billion dollars worth of free publicity.
If the GOP could control which Candidate got airtime, Kasich would have been their Nominee.
You’re attempting to rationalize your conspiracy theory.
But your claim doesn’t stand up to logical scrutiny.