Where can a developer identify the time taken by each process in a transaction using Developer Console log inspector?

A developer is asked to set a picklist field to 'Monitor' on any new Leads owned by a subnet of Users.
How should the developer implement this request?

Given the code below:

What should a developer do to correct the code so that there is no chance of hitting a governor limit?

Universal Containers stores Orders and Line Items in Salesforce. For security reason, financial representatives are allowed to see information on the Order such as order amount, but they are not allowed to see the Line items on the Order. Which type of relationship should be used?

Which declarative process automation feature supports iterating over multiple records?