[Scribus] 2 questions

[Roger]

I downloaded the Scribus 1.3.5 svn yesterday. Thanks.
When I eventually compile, does this overwrite my working 1.3.4 or do I get 2
     working versions of Scribus.
     2. What is the differences between exporting to pdf as <Screen/Web> or to 
pdf as
     <Printer> apart from file size.
     By printer, does this mean Commercial print shop or local desktop printer.
     TIA
     Roger