I was just wondering if I do a bunch of offers while under point based then change the account to referral based will it change the amount of referrals I need to get my gift?
I'm not an expert, but I don't know that you can change what kind of account you have once you've started fulfilling the requirements.
You can change account types at any time. However points do not become referrals.
If you change from referrals to points, every unused referral becomes 50 points (or 125 points on FlashiPods4Free).
But can you change from a referral account to a points account to get the last referral that you need?
You can change, but you'll be short - take a look at the terms and conditions to see how many points you need to get each prize. Then see how many points you have from referral->points conversion (50 for each referral). You'll still have to do several offers. I suggest just trying to get your last referral if you are only one away, it will be much easier. One ref-4-ref trade will only take one offer, and then you are done!