for all the uncerntainty, there are some basic ways to cover a bit, one is your judgement and another is called contract. some people say 白纸黑字 forever is one of hte best ways to prevent bad things happen...
no matter u got an agent or not, since by all means, you most likely will sign the contract with the owner, maybe you can try to ask the owner all your doubts in a very very polite way first and if the answers are somehow no problem we are definatelly leagl, you know things like that;then you can ask the owner in a still very polite but firm way that you want to add one more clause in your rental contract, syaing something like 如果因为屋主的原因而不能履行合同etc, 屋主有义务cover 租户的损失;in order to make the owner feel alright to add such clause, you can add a sub clause like 损失以实际损失或者一个月房租为上限， which ever is lower etc..,
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