1、H1被裁,怎样转H4?有什么手续?需要请律师吗?
you can do by yourself, I-539
2、我先生二月将在中国度假,(机票已经定好)他人不在美国,会影响我转H4吗?还是他提供材料就行了?
yes, 提供材料就行了, and write a support letter
3、如果我再找到工作,H1=>H4=>H1,还要等H1的名额吗?
No,
4、Fire 和Layoff有区别吗?
From immigration point, it is same, you must file before last day.
5、我先生必须于多少天内给我递交H4申请?
see answer for 4