Sure. A few thoughts on this deal, and then the Linden area:
1) I think you got a great deal on the portfolio. That's a small amount of money for a lot of income
2) You need to talk to your lender and get the exact terms. How often can it adjust? Is it linked to prime, and what's the spread? Could it go higher than 10%? Can it go down again?
3) If I'm doing my math right (20% down, 30Y amort), your mortgage payment will be $225. That's only 9.7% of your monthly income. Even if the interest rate goes to 10%, it's such a small loan that it doesn't affect the overall numbers very much.
4) Linden (and Hilltop) is a mixed bag. I would need to know the addresses to give more specific advice. It is a lower-income neighborhood, but that does not mean you can't be very successful, particularly with a good property manager ;) You can buy and hold and be very successful - just don't count on appreciation.
5) Are any of the tenants section 8?
6) How is the condition of the properties?
7) Make sure you allocate plenty of funds for capital improvement.
Peter