Correct. And no problem at all as not buried in ground.It's called clipped direct. But been a while as I mainly push pens in an office now. When I am back in work tomorrow. I will check wiring regs.
If it is a new build the main distribution board will be fitter with an RCD as standard.The only caveat I will put is that the cable will degrade in UV eventually if outside . But you will see this anyway as cable will craze .
If supplying equipment outside ( garage if detached is outside) then best practice to fit an RCD to the circuit. Will likely have been done if new build in last 5 years. At the point it degrades you can put z joint in and replace cable with another type if you want
Not necessarily. Depends on wiring routes for lighting . Sockets must be RCD protected in a domestic environment. The circuit to garage could be a sub main ( unlikely)If it is a new build the main distribution board will be fitter with an RCD as standard.