Dont watermark thumbs
Regarding your idea about too large of thumbs, it totally depends how large and yes, designs require more breathing room between elements now.
LilyChey89, Pornstar page, Live chat, Videos , while i am not a fan of the design and it could be improved on huge, this is an example of large but not too large. and what you were referring to as 'breathing room' i believe
That's about as big as i'd make things