The uploaded files are stored usually under a data directory under the photopost directory but you can change that in global options.
The original file is kept if your settings allow that
The files kept are thumbnail medium(if set to create one) and large( original if you have no resize settings set high where the processor does not touch the file)
Not really sure how to answer that one. The flash uploader allows you to select multiple files from your computer and upload them bypassing any php server restrictions which are imposed upon a normal http upload prompt.
It would i guess replace
vb user albums.
vb user albums are not a photo gallery no where near it. You cant create categories or perform most of the gallery functions the
vb albums thing is a simple user album where users can upload photos to.
There are
vb hooks like displaying photos on the forumhome or the category index on
vb forumhome or profile photos if you choose to install them.