Of the two "warning" messages, the first one is as it's described, so if you have access to the source code, that's something to check out.
The second warning is also pretty common if you output something before the call to the header() function.
You'd have to post some code for me or someone else to look at in order to troubleshoot. Before that, though, have you attempted to contact the person who sold you the script and explain the problems so they can fix it?
