[plt-scheme] Delpoyment/packaging questions

Hello!

Working on PLT-friendly packaging/deployment of SXML tools I've 
some questions:

1. On a Unix (Linux) box an attempt to 'setup-plt' _any_.plt package 
without root privileges fails with:
open-output-file: cannot open output file:
"/usr/local/lib/plt/collects/mzlib/compiled/cmdline.zo" 
(Permission denied; errno=13)

while successful installation of the same package (as root) doesn't modify  
this file!

So, the questions are:
   Why the (output?!) access to this file is required?
   What is modified  (besides the installed collection itself)
in the process of a collection installation?
    What is the proper/recommended way to remove a collection installed?
    ... to upgrade one?

2. It looks that 
strip(1)
corrupts executables created with 
mzc --exe
Is strip in need of some flags or such files are not intended for "stripping"? 

And last but not least: can you point me some docs on the subjects
above? I've tried help-desk (as far as pack.ss), but I've probably overlooked
something...

Best regards,
         Kirill.