I am using a grid productloop style that shows 4 products/paragraphs per row. I want to show the last row with 4 products across. 

I want to show more products on the first page on a department, where do I change this setting?

How can I define the number of products to be displayed per page? 

You can change the Split Pages setting by going to Settings menu -> Global Settings -> Settings for this website -> MISCELLANEOUS

• Locate the “Autosplit page if it contains more products/paragraphs than:”
• As an example, change the value to 40 so that will show 4 products/paragraphs per row (10 rows before the page is split to Page 2, Page 3, etc.) Note: Do not enter a very high number in this setting as it will affect page loading speed i.e.  200 products per page will take time to load. Also, do not enter a negative value here. 

Enter the number of products/paragraphs you want to display on one page in the box (as pictured above). If you want this setting to apply to all websites you build with ShopFactory then you can also change it in New Website settings => Miscellaneous.

• Click OK
• Save and preview in external browser
• Publish your shop again.