I have recently moved, and when I looked at the wiring in the garage it was a disaster waiting to happen.There was bell wire to sockets and generally a big mess of wires.

I am an aircraft electrician by trade but dont know much about house wiring.I have spoke to a local electrician who is happy to, connect it to the consumer unit it the house, and commision it for me once the install is complete.

I am going to be installing:-
3x double sockets (radial using 2.5mm, 30amp CB)
32A MCB is too big for 2.5 radial so upgrade to 4mm or use 20A MCB

2x58w light tubes(1.5mm 6amp CB)
OK

3x Outside lights(indivitually switched 1.5mm 6amp CB)
OK

1xOutoor IP66 socket
16/20A MCB 2.5mm cable or run it with the inside sockets

1x 16amp socket(running a 3hp compressor)
16A MCB may have to be a type C 1.5mm or 2.5mm

The questions I have are:-
1. If I use a 5way consumer unit is it best to split the as above and protect all but the lights with an RCD breaker?
Fine
2. If so what size RCD should I get?
30mA trip, 40A or higher rating
3. What cable size and CB size will I need to run to the 16amp socket?

4. What size cable should I run from the house consumer unit to garage?Garage is on other side of wall from house consumer unit so only needs a hole in the wall.
6mm on a 40A

5. What size CB to outside socket?

Thanks in advance for the help
Jon