Hi,
A little background: my wife and I have around £12k of credit card debt (down from £16k in January

) but it is all 0% interest. Our minimum payments total around £250 at the moment but we overpay and clear around £500/month. We are using about 30% of our total available credit. We have no overdrafts, loans or finance deals. We have one child, and our only childcare costs are paid through the childcare voucher scheme so all sorted before take home pay anyway. Between us, we earn around £40k before deductions.
We have no deposit and around £500 at the moment in savings (intended for Christmas and our upcoming car insurance renewal which we pay in full annually). My parents have offered to help us via the Post Office's Family Link mortgage (or another similar product) whereby the deposit is taken from my parents' property and paid off interest free over 5 years (alongside normal mortgage payments) but our mortgage is secured against both homes. Although I don't think this will be something we are able to do immediately (I've just started a new job and it's temporary initially, plus we don't have enough money saved yet for fees etc), I would like to know if this is something we'd be able to do within the next year or so and if so, what we need to consider.
- I am wondering if the fact that our debt is interest-free is looked upon any more favourably by lenders than if it were a higher APR?
- Also, is it better to reduce our credit card payments closer to applying for a mortgage so that we have more disposable income or better to keep them high so that lenders can see we are serious about clearing the debt?
- Finally, I know it's a fairly new product, but does anyone have experience of the Family Link mortgage or similar? Would I be a more acceptable applicant because the debt is secured against both homes despite my credit card debt or would they consider me a maniac for applying for a mortgage with no deposit and a large credit card debt?

As a first time buyer I feel quite clueless despite having done lots of reading up. I've used a few affordability calculators on bank's websites but as they don't take all of my information into account I'm wary, plus the Post Office doesn't have one for its deposit free mortgage. In an ideal world, I'd wait until our debt was clear (currently looking to be by June 2020) and then spend a couple of years saving for a deposit but when we are paying £625 a month in rent it feels like that's a lot of money to 'waste' over the next 4-5 years if this could be a real possibility. Personally I initially thought it was a no go, but keep hearing of people who have been accepted for mortgages when they thought the same - that they'd never be accepted. So many people have said to me recently, "We didn't think we'd be accepted with our debt/tiny deposit/low wage/temporary job either!" so I feel I should at least consider it, even if you all turn round and tell me I need to get our of fairytale land!
I'd really appreciate advice, particularly from someone experienced in this field or someone who has recently used this product?
Thanks for reading this rather lengthy post!