NRF5340 BLE Mesh setup problem in nrf connect sdk v1.4.99-dev1

[new]

We bought 4 NRF5340 PDK and trying to setup BLE mesh.
As suggested in the getting started guide, there are two BLE mesh example samples from nordic and zephyr.
However, for common BLE examples, it is said that before building any example it is better to program hci_rpmsg to the network core. But it is not mentioned how to configure for BLE mesh examples.
I was able to run BLE mesh light example once but afterward, the board was not recognized in mobile even after rebuilding.

When I tried to flash other board with BLE mesh light control or light switch build error halts the process in "lc_pwm_led.c": 'unsupported board: PWM-led0 device tree alias is not defined".
I would like to know how to correctly set up the BLE mesh light control and BLE mesh light on the board. Following the getting started guide is incomplete.
Other questions like, how to reset the mesh light back to an unprovisioned state after once provisioned.
If we are using nordic BLE sample examples 'light, light control, light switch', is there any guide that how to add more resources such as SPI/i2c, ADC to the same.
Do nordic BLE mesh example uses soft device or HCI of zephyr. What should be the correct configuration to get sample BLE mesh light-light control running?

Thank you.

[new]

Thank you for the reply.

Again an elaborated question.

We bought NRF5340 PDK - v0.8.0

The getting started guide available is not connectable with respect to the compatibility of hardware, software.

Question 1: What is the difference between NRF5340PDK vs NRF5340DK. We ordered last week and got delivered PDK. But in NRF connect SDK v1.4.99-dev1, sometimes it shows nrf5340PDK board is deprecated.

Question 2: How to get started with NRF5340PDK, and what are the examples tested and supported for the board. In the PDK, we can run blinky but not blinky_pwm. The nrf_connect_sdk option in segger embedded studio often throws cmake_error when selected NRF5340PDK for BLE mesh light examples.

Question 3: Does BLE Mesh supported in NRF5340PDK? Only mesh light example is flashing but not, BLE Mesh Light control or BLE Mesh Light switch. Error: Unsupported board, CPU unable to halt, CMake error for selecting NRF5340PDK.

Question 4: How to configure device tree alias for NRF5340PDK. Either overlay file is not found or editing DTS file not affecting any changes. For some examples using the board name NRF5340DK works, and for some other NRF5340PDK. What is the suggested configuration for NRF5340 v0.8.0?

Question 5: What is the actual difference between NORDIC BLE mesh vs Zephyr BLE mesh setup. How to chose a nordic soft device for NORDIC BLE Mesh examples? Does there any setup guide available for BLE Mesh in NRF5340PDK.

Question 6: What are the necessary fundamental kernel or RTOS or soft device architecture knowledge expected for developing a BLE Mesh application on NRF5340. It is very hard to set up even the sample examples and unable to resolve any build errors.

Question 7: Guide me to the resources to actually choose the right combination of NRF_connect_SDK for NRF5340 v0.8.0; replication configuration of the other board setup does not work for all examples.