You need to buy enough insurance no matter LLC or not.

Besides, if you have LLC, then I believe you'd apply loan under LLC? 

1. 投资房在LLC的名下，因房客索赔100万，没办法，房子只有全部赔给房客， 关闭LLC。在这种情况下，

A. 我的损失：投资房的首付10万，即使关闭LLC， BANK不会放过我那40万贷款。

 

If the loan in under LLC, then you won't need to pay.

 

Also in your example, the possibility of bankruptcy is what LLC supposes to protect from.  What if you have more properties that the tenants can sue for?  In general, LLC only works the efforts/troubles when you have enough number of properties or equities.