what are some of Jim's attributes and faults?

Although a great deal depends on the actor's interpretation, Jim's enthusiasm is selfish and empty-headed. He shamelessly leads Laura on, not maliciously but also without any careful consideration. He enjoys her company because, like Tom, Laura remembers his glory days. His speeches praising self-improvement and night classes are symptomatic of the most unimaginative and vapid interpretation of the American dream - culminating in his appalling praise of the lust for money and power as the cycle on which democracy is built. As Tom said in the opening of the play, Jim is more a part of the real world than anyone in the Wingfield family. He is fully a creature of the world and worldly pursuits. He knows what no one else does - that he is engaged - and he still gives Laura the kiss that raises her hopes before he tells her the truth.