Hi,
It seems you are not an experienced PCB layouter .... if so, then good luck.
1) No! This is not a DC circuit. There are high speed signals.
--> On each pin of each IC you should place a fast ceramics capacitor with very low impedance to GND. .. plus at least one big bulk capacitor. For this you need a very solid GND plane.
2) Btw: This violates USB specifications.
The diode makes that the circuit is supplied by the USB...an it prevents current back to the PC in case the circuit is self powered.
Left side = USB side = bus side, thus V_bus is correct.
3) This is usual (maybe mandatory, read CP2102 datasheet) ESD protection. Read about ESD protection.
ESD may cause immediate damage. But - even worse - it may cause a damage that causes delayed fails ... even after months.
Fails may be: increased current consumption, increased heating, loss of function..
4) You may mark them as n.c. If you like. It makes no difference.
Consider to use a bigger value capacitor at EN, to improve programming function. Read informations in the internet about ESP32 programming fails.
Klaus