句1：We will have finished the project by the end of this year.
1.will have done是以后完成时，但老师以前讲will是情态动词表推断，那样我想问，既然是表推断，那可以不能将will换为would，此时用would have done替代will have done表示以后完成时的意义，不同只不过would比will的信心更小，如此理解可以吗？
2.假如该句可以换成would have done，那样该如何不同于过去以后完成时would have done呢，是要从时间状语上进行判断吗？
句2：He may have gone to Americaby the end of this year.
我觉得may have done也是对以后的推断，那样和will have done有什么区别仅仅就是信心程度有什么区别吗？同样的，我能不能换成might have done呢？
句1：We will have finished the project by the end of this year.
