I like your nonchalant approach to character development. Jonathan was all sweating bullets before the broadcast and voila

just like that, Jonathan easily slipped into a different persona.

A very interesting and puzzling way of skipping over the obstacle. Great idea!

As Jonny James, he was lively and charismatic, which made people open up and easily talk to him; his smooth and warm voice like a beacon, attracting a person into a conversation.

I wonder how do you make this assumption as this broadcast is the first in Jonathan's life I presume. Ah, maybe not the first one in his life but only the first one on this radio station. But I guess you feel that the reader is intelligent enough to fill this gap with their own imagination. That's very inclusive of you!

The more I go the more I am surprised. It turned out that Jonny had a magical voice. Perhaps that's why the producers decided that he will be a success. You've made Jonathan such a rich character!

Hm... Interesting development. I didn't understand how was it possible that Trixie called him on the line if he choked her before? But I guess this is not important. Again, you are giving the reader's imagination the benefit of the doubt. That's how it is and you fill in the blanks.

Awesome!