According to the SAP Help Portal1, replacing the search grid in Career Site Builder with tiles achieves the following benefits:
It allows any of the mapped fields to be displayed on the tiles. You can customize the tile layout and content by selecting the fields you want to show from the list of available fields in the Search Tiles tab in Appearance Styles Global Styles (Brand)1.
It allows any of the fields on the job requisition to be displayed on the tiles. You can also use the custom fields that you have created in the job requisition template as part of the tile content1.
It does not allow users to tab through the search results. This is a feature of the grid layout, which enables keyboard navigation through the search results2. For that reason, the tile layout is not recommended for accessibility purposes3.
It does not allow users to share jobs on social media more easily. This is a feature of the Job Details component, which enables users to share the job posting on various social media platforms. This component can be used in both grid and tile layouts. References: Search Tiles Settings in Career Site Builder Global Styles, Search-Related Settings in Career Site Builder, Configuring Search Grid Settings,
[Job Details Component]

To configure the About Us links in the header, you need to do the following:
Create a list type link in the header named About Us. This will create a drop-down menu that can contain multiple links under the About Us label.
Create category type links in the header under About Us that link to the three internal pages. These pages are created using the Page Builder tool in CSB, and they can contain various components and content related to the customer's organization, such as mission, vision, values, culture, etc.
Create an external type link in the header under About Us that opens a new session and links to the page hosted on the customer's corporate site. This will allow the candidates to access more information about the customer's company from their main website.
References:
SAP SuccessFactors Recruiting: Candidate Experience Administration, Unit 2: Career Site Builder Pages and Components, Lesson: Header and Footer SAP Certified Application Associate - SAP SuccessFactors Recruiting: Candidate Experience 2H/2023, Topic Area: Career Site Builder Pages and Components <= 10%

Some leading practices when creating Category pages are:
Page titles should end with the word Jobs or Careers for better search engine optimization (SEO). This will help the career site rank higher in search engines and attract more candidates1.
Category pages use the same design layout to provide a consistent user experience. This will make the career site look professional and easy to navigate2.
Category pages host minimal content to allow candidates to find jobs quickly and easily. This will reduce the cognitive load and increase the conversion rate of the candidates3.
The other options are not leading practices when creating Category pages:
Category pages contain different headers and footers than the Home page. This will create confusion and inconsistency for the candidates and may affect the branding of the career site.
Category pages do NOT contain jobs that appear on other Category pages. This will limit the exposure and visibility of the jobs and may prevent candidates from finding the best fit for their skills and interests.
References: 1: SAP Help Portal - SEO Best Practices 2: SAP Help Portal - Guidelines 3: SAP Learning Journey - Reviewing the Candidate Experience in SAP SuccessFactors Recruiting : [SAP Training - HR832 - SAP SuccessFactors Recruiting: Candidate Experience Administration] : [SAP Certification - C_THR84_2305
- SAP Certified Application Associate - SAP SuccessFactors Recruiting: Candidate Experience 1H/2023]