Hi @Zhong Zhang I have used vacancy hacks over the years to get personal properties under 1% when turning tenants over. 3% increase depends on renewing or getting new tenants, when renewing tenants that's  a safe amount. 

I would still do due diligence such as whole property inspection, lead inspection (depending on when the property was built), appraisal, etc. 

This is basically a math problem that will depend on both you personal finances & also how much of this is an investment vs you want a nice house to live in4.

I think you can go as high as 15% but it's cutting into your margins and depends if you are a GC yourself or not. 150k is close to a million or more.

It is more dependent on that than your experience.

Depends on if you have panels, crazy layouts, etc.

It depends on your financial strength, the quality of the property, how many properties you own, etc.I like to start with one significant expense and three months of vacancy.

There's many more out there depending on what section you want to get into.

There is a not so inexpensive fee - anywhere from 5k to 100k depending on the program and they take a % of each deal. 

@Matt Wan Many lenders require wet signatures on at least the Promissory Note but if yours does not, as a US citizen you could do the entire signing anywhere on the planet with a good internet connection + mic + camera via Remote Online Notarization (RON) for less than $200.If wet signatures are required, the answer then depends upon what foreign country you are in.