Large scale plugins scanning

Hello,

We are wondering what is the best way to automate security scan on large number of wordpress plugins, in an automated way. We want to pull out suspicious lines that will ease finding vulnerabilities.

How much space does plugins.svn.www.ads-software.com consume?
Can we checkout(readonly) the whole plugin repository? Is there another place, where we can pull out files?

Is there a way, to keep track of latest changes in the plugins? Or get a list of plugins modified in the last x days.