If you don’t have a robot or cleaner running around the pool yes brushing will helpkeep the walls clean. I will admit I have a robot I use 1-2 times a week and brush maybe 1-2 times a month. However I have very little debris that gets into the pool. In the spring during pollen season I was brushing weekly
As for pump run time start with pool school. https://www.troublefreepool.com/content/152-determine-pump-run-time
As for pump run time start with pool school. https://www.troublefreepool.com/content/152-determine-pump-run-time