pkgrebuild is a tool to build an pkg package in the filestream format 
from the database of installed packages.

pkgrebuild can produce two different kinds of output:
   - package itself
   - package's pkginfo and prototype files.

You can re-create packages both as root and as-non root user.
Usually, run it as regular user is ok, but:
   - pkg verify may fail due to lack of the read/execute permission
   - you can't package files you have no read permission for.

For UnixWare (at least UnixWare 7.1.1) we have additional problems:
   pkgmk (used for actual pkg building) for some reason try to open
   /dev/resmgr for reading, but default UnixWare installation
   set permission for /dev/resmgr to 600, so it's fail.
   (Really, in default UnixWare configuration regular user can't
   build package. Cool, isn't it ?)
   To fix it you may as root:
      chmod +r /dev/resmgr

   Another UnixWare's problem is a permission for pkgchk - program
   for verify package integrity. Again, for some unknown reason,
   it has permission 500, i.e regular user can't verify package.
   To fix it you may as root:
      chmod +x /usr/sbin/pkgchk

I don't think these changes create any security problem.

Re-creating packages' prototype and pkginfo as regular user is ok.