updates on site modifications
So for the collection grid, I added a new section called 'Featured Collection Grid' this one behaves as it should (original theme), you can check the options (product per row etc...) you can also enable or disable 'swipe on mobile'.
BONUS: options to change spacing top and bottom of section.
For the auto sliding items, I made it an option, so when using 'Featured collection' you have two options to 'enable auto rotate' for mobile and/or desktop.
*if you want to remove this options completly, in the file 'featured-collection.liquid' i added a comment to the section to delete. easy to do.
For the header, I made it as the original theme had in mind. it hides when scrolling down/show when scrolling up (but shows properly without previously weird spacing). You can enable the stick header the header options also, so it just stays where it is.