LNA isn't simply a high gain transistor, it stands for LOW NOISE AMPLIFIER, and as such doesn't mention the gain at all - transistors at the microwave frequencies used only have fairly low gains that high. It's all about signal to noise (as you said), and high gain doesn't mean low noise.
I've built plenty of equipment in the past, including valve gear for VHF.
You claim to have been a ham for 36 years, yet you have no idea how to wire a simple volume control - you've had two tries, and neither were close to been correct
Don't you have to take the RAE over there?.
Oh, Nigel. Did you look me up on QRZ? I'm for real.
Remember we've all been explaining what AGC is to you - perhaps you should have listened.
The sections of circuit you've posted has far too many stages, most doing absolutely nothing, and your audio AGC idea is what you would might on a direct conversion receiver, where you have no RF or IF amplifiers to control.
Why would you want class A for low quality SSB signals?, in any case, all low signal audio stages are class A - it's not like you have an option
Your output stage won't be class A though, and no reason for it to be so.