First house for a young man

Hi all. This thread is to ask opinions about buying my first house.
As I'm progressing in my degree program, I'm about to graduate, and I'm
expected to stay as a postdoc for at least 2 years. Depending on future
situation, I may stay as a faculty, or I may leave and find a real job.
I plan to buy a house, for both investigation and to reduce cost of
living. As someone might have heard, economy bubble is collapsing in
China, and my parents' want me to buy a house in US as a safe deposit in
case Chinese currency collapses. In the meantime, here (RDU
metropolitan), real estate's value gains about 10% each year, while tax
is only 1.03% (Raleigh city+Wake county), besides evaluated taxable
value of houses is overall lower than their real market value.
So, long story short, I have $260k on hand (my parents sold one of their
apartments used for renting, and I sold my 2 small houses for renting,
both in China), and my parents can get me another $10k~$20k if REALLY
needed. I plan to buy a small townhouse in Raleigh/Cary, NC with this
money.

My questions:
1. Should I spend all the money (read: ALL) on a house that leaves me no money at all (maybe a few k$ in
checking account, but that's it), or should I buy a cheaper house and
spare some money in case of emergency? Right now I have 2 choices: a
$270k house, including all costs, and a $220k house, including all
costs, both townhouses, both are of similar 1700 sqft construction area,
both have 1 garage+2 front door parking, the more expensive one has 3
bedrooms (so the rest 2 rooms can generate renting revenue) and is built
in 2012, while the older one is a 2006 house with 2 giant bedrooms
(despite giant, a single bedroom is worth the same from a tenant's eye).
2. I can generate ~$500 per month revenue per bedroom, and that means each
year, I can make $12k from the $270k house, and $6k from the $220k
house. Factoring in that, which one is my best choice?
3. Should I buy a house from the first place? I do NOT have a green card or H1B. I'm
on F1 visa, but I'm sure if working in university, I have 100% chance
to get H1B if my OPT runs out. In the meantime, I have confidence to get
100 paper citations (which qualifies me EB1 NIW green card program).

Inputs are very appreciated, as I'm about to pull the trigger very soon.