Consolidating your debt can be a good idea, but it sounds like you'll be elimination debt on 2 properties and increasing it on another. At 70% LTV you should be able to get a competitive loan, even for non-owner occupied. Talk to a creative local lender to work through the various issues which will come up in the process.
As far as your credit score is concerned, an inquiry costs about 3 points, but you can have multiple inquiries in a 10 day period with different lenders and only be hit once if they are all mortgage lenders. The overall effect is hard to judge because in theory you're overall debt will be roughly the same, but you'll be encumbering one property so much heavier. I'm not sure I'd make my score a decision maker in this, it really comes down to whether or not the total deal makes sense and improves your cash flow.