Mr. Towers Chandler was pressing his evening suit in his hall bedroom. One iron was heating on a small gas stove; 

the other was being pushed vigorously back and forth to make the desirable crease that would be seen later on extending in straight lines from Mr. Chandler's patent leather shoes to the edge of his low-cut vest. 

So much of the hero's toilet may be intrusted to our confidence. The remainder may be guessed by those whom genteel poverty has driven to ignoble expedient.

请教老师：

1）extending in straight lines 应该是现在分词作 desirable crease 的 后置定语吧？

2）没看懂 those whom genteel poverty has driven to ignoble expedient. -麻烦老师分析一下成分，尤其是没看懂

those, who, genteel poverty 之间的关系， 以及这里的driven to - drive to 是何意？