Half-Bridge Gate Driver Circuit Question
The boost capacitor needs to be large enough to be able to supply the gate charge required by the high-side MOSFET on every switching cycle without significant voltage droop. A small capacitor might charge quickly, but it discharges quickly, too.
Generally speaking, the boost capacitor should be at least 10× to 100× the effective gate capacitance of the MOSFET, but 47µF sounds excessive to me.

The gate resistor helps to suppress parasitic oscillations at VHF frequencies that can occur with large MOSFETs (gate-to-drain capacitance resonating with the parasitic inductance of the gate connection), which is important both for efficiency and for EMC. It should be mounted as physically close to the transistor as possible.