Gabriel has become so fearful of going outside of his home alone and of being in open spaces such as parking lots that he has difficulty holding a job. this is best described as

Agoraphobia

Explanation:

Agoraphobia is the fear of open spaces and places. Gabriel will find it increasingly difficult to go outside.

in this scenario it would be the consumer demand as most influential in making the decision. the band members need to figure out where and from whom they will make the most money, in other words who out of the two consumer groups - football fans or car drivers - will spend their money, who is more likely to contribute to their cause and buy what they are offering.