RE: 2.4 GHz... Will one transmitter work with other brand recievers?
The ASSAN and Corona radios sold by Hobby City are FCC and CE certified. I have them and fly them regularly. They are not crap.
They are cheap enough so that if you get a bad one just throw it away and get another one.
I have three transmitter modules and four receivers. I haven't got a bad one yet.
I order from HC and usually receive what I ordered within about 10 days.