Hi,
2) check this screenshot, you should only leave 1 image
https://www.dropbox.com/s/0xmjjifvz1pkir3/several_images_portfolio.png?dl=0
3) It was necessary to edit the portfolio asset to change the Portfolio type from standard to Gallery.
You shouldn’t do that to your Portfolio item titles, because that will appear in the mouseover.
The second line of the mouse over displays what is inside Portfolio meta -> Custom excerpt.
4) For several reasons you shouldn’t use the Portfolio title to do that, it’s not meant to be used like that.
It should be used instead some custom field in each Portfolio item, and would be necessary code changes to get that value and display it where you want it. Unfortunately that’s outside of our support scope.
-Rui