[saranbr]

From the top--
--Bad credit will only be a problem if you need to borrow money to adopt. Basically they look at your income, not your credit score.
--Diabetes- Probably not unless he's disabled from it. Most, at least adult onset types, are still capable of a "full life span" or other such thing the agencies are generally looking for. But, a good question for the agency.
-- Other children-- depends on the country you are interested in. I know there are several or at least a couple people on this forum who are in the process of adopting from Guatemala and already have 4+ children. Some countries have a limit of three to four, but have the "case by case" exception policy, which might work if you have children leaving the nest soon.
--Overweight-- this will probably come down to the doctor's letter. Usually Guatemala at least wants something saying that you have a normal life expectancy and are capable of raising a child. Unless you have major secondary health issues, I doubt this would be an issue.
Best wishes on your journey!!!