Several questions

I use the Joker theme and I would like to know how to:

– use less space between the photo and the upper menu bar in (e.g. twenty twelve)?

– use less space between the photo sides and the next / previous arrows ?

– use less space between the photo and the thumbnails ?

– what are the Base Width and Base Height values for? I changed them, but could not see any difference ?

– sort the pictures in a gallery ?

– remove the name of the author ?

Thanks for answering and the plugin looks nice.