B. -
Can you sell your townhouse and be above water? If so, then I would suggest selling it and then buying a new house. I'm in Broward County - and I know that the market isn't any better in Miami-Dade.
Issues here: you will loose your homestead exemption on your townhouse property taxes as soon as you are living in a new house. You can only claim homestead exemption on the house you are living in....thus, you will need to consider whether the rent you can get on your townhouse will cover your mortgage, association fees, insurance, and property taxes as well as maintenance. Keep in mind that most renters expect that the house be freshly painted before moving in and you will have at least some repairs each time you get a new renter. Plus, although there are more renters today - they may not have good credit histories and are more likely to not fufill the terms of the lease.
Also, as soon as you have renters, you open yourself up to the possibility of lawsuits. I learned this the hard way when we were renting our townhouse in VA and the tenant claimed he slipped on the sidewalk outside and sued us. We had good insurance and they paid but still, it was a year of trouble/headache and honestly, the fact that he slipped on the sidewalk was not due to our negligence.
Finally, in this market, I would seriously not take out a home equity loan (higher interest rates plus the fact that home equities are still falling down here!) instead of a mortgage. The home equity loan ties the two properties together whereas mortgages keeps them separate.
Full disclosure: I am a financial planner in Ft. Lauderdale - this would be my advice if you were my client. Let me know if you have any further questions.
C.