Quick answer is that srpms are source rpms--they aren't the binary, they're what can be used to build the binary rpm package.
Apparently, it's an older rpm--something like Unknown tag is always a bad sign, meaning that something in the nature of rpm syntax has changed. It's probably now license GPL instead of copyright. Or, it may be made for a different version of Linux
Generally, one installs an srpm file then builds it in their home directory, rather than using root.
Although that is about building from scratch, rather than building from an srpm.
Might also be of use.
Looking at the spec file, they say it's being built for Mandrake and RedHat. You might find it quicker to try to build from the tarball if you have any experience with that. Looking at the instructions for building from source, seems pretty easy and probably easier than whipping the rpm into shape if you aren't experienced with doing that (and your question about what is a srpm indicates that you're probably new to this.)