Just by looking at this forum you can see how many approaches one can take: pre-foreclosures, foreclosures, REO, short sales, HUD foreclosures, rehabs, bankruptcy sales, short sales, the list goes on.

If the one deploying member requests to be out of the lease, am I legally allowed to declare that lease invalid?

They the turn their aggregated income all on paying off one property, get it done, and then move all their augmented aggregated income to the next property, get that done, and rapidly snowball all the money to paying everything off.There are all too many others, however, who base their business model on perpetual growth, think their spreadsheets are magic and will always work out month after month, smugly believe they've calculated for every possible manifestation of Murphy's Law that could hurt them, and just keep on acquiring and acquiring (and inflating and inflating their lifestyles) until something breaks their positive cash flow prediction model for a month or six and they go swirling down the toilet to a bankruptcy they never saw coming.When you owe someone money and you've committed to paying them over a schedule, there are always risks.

For example:AccountantsReal Estate AttorneysEstate Attorneys/Bankruptcy AttorneysProperty ManagersMany of these professionals will know when their client is hoping to / needs to sell their property and can be a good resource for finding motivated sellers.Hope this helps!

Prospective tenants should be screened for prior evictions, judgments, liens, bankruptcies, criminal history, sex offender registry, terrorist activity, and credit worthiness. 

I have couple of friends outside United States  (Non US citizen) that have never declare taxes here, that are interest in acquiring properties for investment in Houston area , what options of financing would an expat have here in Texas ?

If the prior foreclosure was foreclosure on a Deed of trust the the prior foreclosure could have been reversed due to improper notice or posting or last minute filing of bankruptcy.

Protecting one spouse and his/her assets in case the other one gets deep in debt and ends up in bankruptcy.7.

I think it clear that definitively declaring one a better investment is impossible and at a the end of the day both are solid.

Some of the most common examples of "undue pressures” include:• A seller who must sell quickly to avoid foreclosure or bankruptcy • An estate in probate that must be liquidated quickly • A tax sale or bank REO where the seller is willing to take less money just to get the property off of the books. • An investor wholesaler who is willing selling his property at a deep discount to avoid rehab costs or to obtain a quick sale.These types of sales are typically not good indicators of fair market value.