I would like to include some png files as design elements so they keep their transparent backgrounds - or is it better to create them as tiffs so they keep the exif data then upload as zips and do you also upload a jpg?   I know I saw somewhere what do do about these type of files but cannot find it at the moment, can someone help please - in non-technical terms

I am still getting the hang of png's so please bear with me and let me know if this is correct.

They can be resized without loss of detail so  it is probably worth just including the original size ?
..  and pricing according to detail of work involved?

What are the benefits of including a zipped tiff - would the exif data be included/uploaded as it seems that png's don't retain any data

Do the zips and pngs get downloaded together?