Does Reducing Flow Increase Pressure?

The reduced flow would reduce the pressure loss in the pipes, resulting in more pressure.

Will reducing flow reduce pressure?

Choking off your supply by closing down the inlet valve flow area will only reduce pressure downstream of the valve as long as you have flow through the pipes (that's Bernoulli for you). The second you stop flow the pressure downstream will equalize to the same pressure as upstream of your valve.

Does restricting flow increase pressure?

The short answer is: no. Flow and pressure are linked, so all other things being equal, increasing the pressure will increase the flow out of a restrictor.