Validation rule is a tool that can be used to enforce data quality and business logic by preventing users from saving records that do not meet certain criteria. In this case, a validation rule can be created on the Lead object to display an error message if the Lead Status field is marked as qualified and the Budget field is blank.
References: https://help.salesforce.com/s/articleView?id=sf.fields_about_validation_rules.htm&type=5

A pending Chatter post is a post that has been scheduled to be published at a future date and time. However, if the user who created the pending Chatter post is deactivated before the scheduled date and time, then the pending Chatter post will be canceled and will not be published. This is because deactivated users cannot create or edit posts in Chatter. References: https://help.salesforce.com/s/articleView?id=sf.
collab_scheduled_posts.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.
collab_deactivated_users.htm&type=5

Discount is not a standard field on the Opportunity object, so you need to create a custom field to capture the discount amount or percentage for each opportunity. To set up an approval process where opportunity discounts over 30% need to be approved by the VP of sales, and any discounts above 10% need to be approved by the user's manager, you need to configure two separate approval processes with different entry criteria based on the discount field value and different approvers based on their roles. References: https://help.
salesforce.com/s/articleView?id=sf.approvals_getting_started.htm&type=5

To use as an identifier when importing and updating records from a separate system, an administrator should use External ID field type on an object. External ID fields allow storing unique identifiers from external systems and using them for matching records during import or update operations. External ID fields can also be used for upsert operations that insert new records or update existing ones based on external ID values. For example, an administrator can create an External ID field on Account object that stores account numbers from an external ERP system and use it for importing or updating accounts from that system. Rich Text field, Record ID, and Auto-Number field are not suitable for using as identifiers when importing and updating records from a separate system. References: https://help.salesforce.com/s/articleView?id=sf.
fields_about_field_types.htm&type=5 https://help.salesforce.com/s/articleView?id=sf.data_loader_upsert.
htm&type=5

Screen flow allows you to create a form that collects user input and performs actions based on that input. You can use screen components to display questions and instructions, and use flow logic to update records or send notifications.
References: https://trailhead.salesforce.com/content/learn/modules/screen-flows/get-started-with-screen-flows
https://help.salesforce.com/s/articleView?id=sf.flow_builder_overview.htm&type=5