Just fit a mechanical pump.
With the electric pumps, if you are running a carby your electric pump is pushing out about 1.5 - 3psi but if you are running injection your pump could be pushing out 90psi. So you are more likely to blow off a hose with injection than carby.
If you have a switch on the alternator the car may not start when cold because you cannot crank it fast enough to run the alternator.
If you have a switch on the oil pressure it will not start until the oil pressure builds up which is a good thing!
You could fit a mercury switch that will cut the pump if the car rolls over.
You can fit a G switch but they can be a pain on a rough road because they can get triggered by pot holes and stiff suspension.