The 50Amp fuse is for the radiator fan(s)
Small fuse - 15Amp - Variator solenoid, Variator relay coil, air flow meter, Lambda probe heater, throttle idle actuator, fuel vapour recovery solenoid.
'Main' relay ( S41) 30Amp : Fuel injectors, supply to engine ECU, fuel pump relay coil, supply to the 15Amp fuse above, plug coils, injectors.
The above relay can be identified by the following wires : Purple-black, red, red-white, orange and green/black
Phase variator relay ( S12c ) 30Amp. Wires : 2* purple-black, red-green and red
Aircon compressor clutch relay ( Q22 ) 20Amp. Wires : Brown, Red, Orange and Brown-black
Compressor auxiliary relay ( Q32 ) 20Amp. Wires : Orange, Red, Green and Grey-Yellow
The connector on the far left is the lambda probe.
I suspect that the car did, at one time, have aircon. It's likely that someone removed some of the components in the engine bay. Maybe to save weight
I wouldn't worry about the make of the relays. They're fairly standard. The red relay base intrigues me a bit. The aircon sockets are supposed to be grey according to the workshop manual and the other two black. But I wouldn't put too much faith in that!
As to the car stalling, maybe the relay is broken? Could be one reason why the aircon was stripped out!