Not sure what to do - mortgage application in 2-3 months

AliceBanned

I have 4 credit cards which I am paying off at  £750 monthly - current balance just over £6000. One of the cards (balance £3000) runs out of its 0% deal on 20th April - I recently was accepted for a Virgin BT card in December but the deals have run out on that and my other cards. The MBNA card will be at 29.9% when it runs out. 

Should I apply for a new 0% card or will that impact too negatively on my mortgage application? I have worked out that interest would be around £70 if I don't do a BT and pay it off by the end of the deal, but I want to apply to remortgage soon so not sure whether to just take that hit of the cost of interest to avoid jeopardising mortgage application.
I have only just put current flat on the market and the market seems slow. I do need to save a bit for the legal fees too so don't really want everything to happen too quickly. Will probably rent in between properties anyway as this will be cheaper in the area I live compared to current (shared ownership flat) costs.

swaledale_one

When I've played with different mortgage calculators they seem to favour credit card debt to fixed loans ie when I put my 5k loan monthly payment in it gave me 25k less than if I put that I owed 5k on credit card, so i wouldn't be to worried about switching to a new 0% credit card.