@Nathaniel Busch I thought you could only claim to be a first time homebuyer again if you didn't own a property in the most recent 2 years. As in you sell one, then purchase another. I'm not sure you can own property, move to an apartment, then qualify as first time homebuyer again. If you can then do let me know!!
@Matthew Trotter yes, you can withdraw the principle from your Roth at any time for any reason. I think the account would have to had been open for 5 years. Double check that.
In terms of a 'first time homebuyer loan', those are normally open to persons that are low income. They are normally regulated at the state and city levels. Your real benefit is being able to owner occupy regardless of income. I know that right now conventional loans can have less than 20% down. The bank you compensate by giving a slightly higher rate. This still beats FHA because there is no PMI for the life of the loan with conventional financing.