DRV8353: DRV8353 SPI Register programming

Tool/software:

Regarding Register programming especially W/R ones where deice is configured for specific performance. Table 15 is shown below but questions apply to other tables as well. 

1. Does LOCK apply to all registers not only Table 15 where it is defined ?

2. Can we change only certain bits in a register without affecting others?

2.a Do we have to read register first mask out the bits modify and rewrite?

3 When we unlock does it unlock to all registers?

4 Is there a sample register setup and modify program or process flow chart?

is there a