What would you do if you were in my place?

What would you do if you were in my place?
If paul were my son,I just not worry.
Allen is in the basement, trying to repair the washing machine.
1.in the basement, in my place在上面句子充当表语?介词短语在句中一般做什么成分?
2.上面的两个were都是虚拟用法,对一般现在时的虚拟用一般过去式?
3. trying to repair the washing machine是（who is ）trying to repair the washing machine作定语修饰Allen还是现在分词短语作补充修饰主句?