When faced with the agony of getting jobs after graduation, a hapless hair metal band goes on the road trip from hell for a shot at a huge record deal but a jaded former classmate works for the label and will stop at nothing to see them flop.

Why MUST they get a record deal? Most bands and musicians want a record deal, what is different about this band that makes their story of getting a record deal worth telling? In other words, what is the specific event that motivates them to take action in order to get the record deal?

Secondly, what is at stake? So what if they don't get the deal, what's the worst that will happen? Much like many other bands they'll all get jobs and move on with their lives?

The jaded classmate can be cut, he isn't presenting any SPECIFIC obstacles in the logline - "...will stop at nothing..." means nothing, as it doesn't describe and specific event or action. However, if he were to be in a rival band who are also targeting a record deal with the same label then the obstacle is made clear.

For example:
After their lead singer is diagnosed with throat cancer, a metal band have one a month to score a record deal before he loses his voice forever.

This isn't very good but it illustrates the idea that as a result of a single event the main characters became motivated to take action in pursuit of a single goal. You could make it terminal cancer so he will die instead of just lose his voice and the same applies only a bit more morbid.