He soon found it easy to make more money by thieving than his father had done by a lifetime of honest work.

语法书上说这是定语从句。

1）done替代了made, 但是我记得http://ask.yygrammar.com/q-35984.html 语法探讨老师说了

“...但定语从句不允许采用动词替代式，did为错误。必须将did改为had.”，由此，我得出结论要使用had made, 而不是

句中的had done, 我的观点对吗？

2）上句可否看成比较状语从句，而不是定语从句呢？如果1)是正确的观点，并且如果可以看成是比较状语从句，是否意味着可用done代替made呢？

3) by a lifetime of honest work 如何翻译？可否改成by honest work of a lifetime？二者究竟有何不同？另外，可否说during/in a lifetime of honest work 呢？