Posts customization

Hi

Could anybody help with easy solutions? I use PR News theme (https://pr.premiumresponsive.com/).
1) Is there any solution to disable post thumbnail opening? I want the post thumbnails featured images in it be all shown in first page, but the single post contents I would like to open step by step (like christmas calendar for example).
2) How could I link post thumbnails directly to external url (unless post opening)?

Thanks to all answerers!