Negative Entry removal, consolidation loan & negotiation with original debtors

Background: I had flawless credit (700+) up until 4 years ago when I lost my job and did not have income. I've gotten a foothold on my finances again and I'm trying to rebuild credit. I'd like to get an apt and move out of my house, but my credit score is below 590 right now.

1) I have 3 legitimate debts that I owe for credit card balances. On is with Amex and I will negotiate with them directly. The other 2 are with collection agencies... I tried to verify one of them and they sent me a letter saying they would look into it, reported the debt as disputed, but continue to send me requests to settle the debt... it's been 6 months and they still haven't verified... the remaining collection agency has sent 2 vague letters saying legal action will commence if I don't pay them. Isn't this illegal to threaten legal action w/o following through? If you think I should deal with these 2 agencies, what's the next step?

2) With these 2 debts in the hands of collections agencies, it it better to call the original debtors (Chase and Bank of America) and negotiate to have the entries removed if paid in full? I had long standing excellent payment histories with all my credit cards before I had financial issues a few years ago. My plan is to get a consolidation loan so I can get just one payment and at the same time improve the credit report. Will a $12,000 loan under my name hurt my credit (I'd be getting a cosigner)?

3) There is one pesky entry on my credit report that I cannot find any record of. Asset Acceptance LLC had sent me a few letters for a debt but it never belonged to me... I sent 2 certified DV letters and never got a response although I got return receipts for both DV letters. This debt is for $18,000 (reported to all 3 bureaus, last update was 08/2007) and this is really hurting me now. I filed a complaint with the FTC on their website already. What next? Should I sue them?
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1 if the debts are yours they can sue. If they do not verify the debt you may have a way out legally. negotiate would be the next step

2 it is always best to negotiate with the original creditor. You might find the debt was charged off on the companies books and then possibly sold for .40 cents on the dollar. They would not tell you that. But if they say it is out of thier hands and has been sold to collections then, you can guess that the collection agency only has about .40 cents on a dollar or les in the note. So you might negotiate with them for a lesser amount.

3 if is not yours and you filed a complaint and that does not stop collections then, I would seek out a credit lawyer. I do not know where to send you to look for one.
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This has been quite helpful, thank you! Please share this on your amazing blog!
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