Answer to Question 1
This is because heat can either be rejected or absorbed by the outside unit.
Answer to Question 2
The customer often judges a technician on the appearance of their tools. It is harder to work with poorly maintained tools, and a tool bag that is not well organized makes it take longer to locate the tools for the job. The way you maintain your tools reflects on your quality of workmanship. Clean sharp tools are better to work with and safer to use.