Help: from DMP to F&F

Hi everyone
Before I get into my problem, let me say what an amazing lot you all are, helping each other.

I’ve been on a DMP with SC for about 3 years and can’t recommend them enough. I’m still on a DMP with them and I recently made a girlfriend who is willing to help me pay my debts with some of her savings. Although she can’t afford to give me all the money, she is willing to give me £9000 to pay something towards my debts. I’ve been reading about F&F offers and I’m thinking about trying to make offers to settle as much as possible, rather than pay one single debt.

My current debts are:
Aqua Newday: £1500
PayPal: £2000
Cabot Financial: £1900
HSBC repayment services (cc): £4000
HSBC repayment services (pers loan): £8000
HSBC repayment services (OD): £1900
HSBC repayment services (pers loan): £1901
More or less £100.

I have been paying £180 / month towards my DMP for the last three years, which is split between all my creditors.

Questions 1:
When I send a letter to HSBC repayment services with F&F offer, do I make one offer for all my debts with them, or I need / should make separate F&F offers quoting the account number for each debt? Do I send one letter or 4 separate letters?

Question 2:
How much should I offer to each creditor? Can I make offers to HSBC only and continue paying monthly payments to the others?

Question 3:
Shall I go self managed dmp before making the offers? Shall I pay £1 / month for a few months before making the offers?

Question 4:
What would you do if you were me? I'm trying to come up with the most efficient solution but I don't know which one is effective.

Any advice is highly appreciated.
Thank you very much!