As for problems:
Mortgage: take some time to learn about points and the different types
of loan packages out there. There are pros and cons to different
options. No down payment sounds great but there are drawbacks. Some
mortgages are only good if you're planning to stay in the same house
for more than 5 years.

Obviously a house that needs some fixing might be cheaper, but if you
don't know how to use a hammer or have a busy hectic schedule that
you'll never have time to fix things, you might not be saving all that
much (or be living with a plastic tarp for a roof for years).

A good real estate agent and mortgage broker should take the time to
explain these things to you. If it sounds too good to be true, there is
a possibility that it is. That's all fine with a small purchase, but
something that comes with a 30-year mortgage is a different story.