You will not qualify for a mortgage until you learn to pay your bills on time. You do not show a willingness to pay your bills and everyone checks your credit except the Bank of Parents.
You need to go to your local nonprofit housing group for credit counseling. Unless you got out of college 2 years ago there are some other reasons why your score is so low. The credit counselor will go over your credit report with you and tell you what actions you need to take. Listen to them. Until your score is in the mid 600s you are paying more for car insurance and home owners' insurance (if you could even get it).Now is not the time to buy.
Where are you located? The lender origination is very high!
The underwriter is nervous about your wife's income and wants to deny the loan. No one that is a small consultancy has audited books. The question becomes do you qualify for the mortgage on your income? If so speak to the manager about changing your application to leave out your wife's income.
You are definitely wasting your time. A DU (desktop underwrititng) takes me 5 minutes to do. I do check your last month's paystubs, last 2 years of W2s and tax returns, and your last 2 months of bank statements. If the DU says yes and you have the income and money requested, you get the preapproval.
You can speak with a mortgage officer who is trained in FHA mortgages.
There are lenders that will do the refinancing of an investment property if you owe 10 or less properties. There are some private lenders who would do the cash out up to 65%.
You will need to put down more then 4% once you get your Social Security number since you have no US credit. Expect 25% down minimum.
After a bankruptcy was discharged you need to wait a minimum of 2 years for a BK13 and 4 years for BK7. In both cases you need to re-establish credit.
FHA does not consider medical collections. If you pay your other bills on time and you explain why the bill is in collection, this will not be a problem.