Two functions that an administrator should use when creating a validation rule are:
Error condition formula, which defines when an error should occur based on record fields and values Error message location, which specifies where on the page layout an error message should appear when triggered by an error condition formula Formula return type and rule active date are not functions used for validation rules. Reference: https://help.salesforce.com/s/articleView?id=sf.validation_rules_overview.htm&type=5

To display only the proper lead sources based on the product category chosen, an administrator should create a dependency between the Product Category field and Lead Source field on Lead object. A dependency is a relationship between two picklist fields that restricts the values available in one picklist based on the value selected in another picklist. For example, an administrator can create a dependency that shows only Online Store and Social Media as lead sources if Product Category is Shoes, but shows only Trade Show and Magazine as lead sources if Product Category is Apparel. Creating a page layout for each category, creating business processes and record types for each category, or creating a single business process with record types for each category will not display only the proper lead sources based on the product category chosen. Reference: https://help.salesforce.com/s/articleView?id=sf.customize_dependent.htm&type=5

To track assigned licenses and permission sets in Salesforce instead of using a spreadsheet, an administrator should use User Report type on Report object. User Report type allows creating reports that show information about users such as their profile, role, license type, active status, login history etc. It also allows adding fields related to permission sets such as Permission Set Assignments or Permission Set License Assignments. For example, an administrator can create a User Report that shows user name, profile name, user license name, permission set assignments count etc. Login History, Lightning Usage App, or Permission Set Groups are not features that can be used to track assigned licenses and permission sets in Salesforce. Reference: https://help.salesforce.com/s/articleView?id=sf.reports_report_types_standard_user.htm&type=5

The Opportunity Stage Duration report is a standard report that shows how long opportunities spend in each stage before they are closed. It can be used to measure the average stage duration for all closed opportunities by grouping and summarizing the data by stage name and duration fields. Using process builder to capture the daily average on each opportunity is not feasible because it would require creating multiple fields and formulas on the opportunity object and updating them every day. Adding formula fields to track stages on each opportunity is also not practical because it would require creating multiple fields and formulas on the opportunity object and maintaining them every time a stage changes. Refreshing weekly reporting snapshots for closed opportunities is not necessary because the report can run on real-time data without snapshots. Reference: https://help.salesforce.com/s/articleView?id=sf.reports_opportunity_stage_duration_report.htm&type=5

Dynamic dashboards allow you to display data according to the security settings of the running user. If users have different access levels to data on dashboards, you can use dynamic dashboards to show them only what they are allowed to see.