Basically, the software centre is reporting to you certain ‘points’ as they relate to Debian’s Policies.
They are not errors as such, and are just pointing out to you the lie of the land as they relate to Debian policies, typically or as often as not as they relate to “free” and “non-free” libraries or components.
Another option would be to install and use the gdebi package installer, which is able to give you more details of lintian output/info when using it to install .deb packages.