Ok...it took me a bit of time to figure out how to hide files in a folder but show the sub-folders, but I think the following will work for most cases:
Use a Visual Filter (which are documented in
http://88.191.26.34/XYwiki/index.php/Visual_Filter) of the following
Now if there are any files without an extension, which is typically unusual, they will still show....so it's not perfect, but may do for now.
I couldn't recall any other existing way to do it...but then, I've not had a reason to do so either.
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Now regarding larger icons: Personally I find the existing icons large enough and I'm having some serious vison issues, but that's just my opinion...and given the amount of icons I have in TB, there is just no room for bigger ones...
However, I did find the following prior threads:
http://www.xyplorer.com/xyfc/viewtopic.php?f=5&t=1621
http://www.xyplorer.com/xyfc/viewtopic.php?f=3&t=2429
and based on the 2nd one, which is somewhat recent, it doesn't look like it will happen.