Amplifier circuit doesn't work (what am I doing wrong?)
Ideally, you need about 0.5 to 1V on the emitter which means 1.2 to 1.7v on the base. Simple inspection tells me that 1k for R4 is too low and this is confirmed by your belief that it should have 0.6V across it. Try something like 2k7 for R4. This should give you: -

\$20 volts\times\dfrac{2700}{30000+2700} volts\$ = 1.65 volts

This will give you about 1V on the emitter and there will be a current thru R2 of 1mA. This will translate to a volt drop across the collector resistor (R1) of about 10V and this is about right for quiescent operating conditions on a 20 volt rail.

If you are really using 100 Hz as the input you might want to make C2 a bit bigger. At 100Hz it has an impedance of over 1500 ohms and this might be too high given the resistors R4 and R3.