The IRD serves 2 distinct purposes (1) as a differential for the front wheels (2) as a power take off for the rear axle. The 2 parts are reasonably separate in their operation within the IRD. I am pretty sure that when the IRD fails through wind up (which is what's happened to you) the front diff is not affected.
Therefore removing the props will allow 2WD operation quite happily. However (there's always 1 isn't there!) simply removing the props still leaves the parts f the IRD driving the PTO functioning. The banging you hear is the gears in the PTO trying to engage but slipping - it is a cringing horrible sound as if someone is whacking the box with a sledgehammer. If you simply remove the props the noise will probably stop or change to a ticking sound - however they are 'loose gears' that will be turning and give a good chance of jamming - this will either locks your car's transmission, or more likely shatter the case of your IRD - you are up **** creek then because as well as needing a recon IRD - you'll get no rebate for a swap unit.
As well as removing the props, you therefore also need to remove the rear pinion on the IRD and replace it with a blanking plate. This removes one of the gears that was slipping and you should be safe to then drive it 2WD. Keep the pinion and when the time comes to get a recon IRD you will get a rebate because you have the whole unit. Don't forget to replace the VCU at the time you replace the IRD as well.
You are going through what I went through 2 1/2 years ago (although mine went through a tyre low on pressure). Its what bought me to LZ to find out how the Freelander's transmission works! Unfortunately the IRD going bang is all-to-often the way people find out how Freelander's transmission works.
You'll have to tell your insurance company you are running 2WD. Over here, by the letter of the law, you would also need to put the car through a 'compliance test' as its seen as a major change to the car. You don't have to in the England, but you do in Northern Ireland I believe - not sure on other places.
Because of this need for compliance (it would have cost $$$) I opted to still run with props, keep the IRD 'whole', renewed all the bearings in the IRD but removed the pinion gear on the end of the rear pinion. So my props are being turned by the rear diff. Knowing what I know now though, I would simply have removed the pinion gear and only renewed the bearings in the rear pinion.
My rear diff was not affected, its been turning the props for 1,000s of Ks and makes no noise at all. If your rear diff does make noise after the props are taken off, you will probably need to address is for the same reasons as 'lose gears' in the IRD is a no-no. Don't be tempted to remove it and the drive shafts (to the rear wheels) - the ABS wont work and your rear wheels will fall off! You can remove the diff and drive shafts, but you need to retain the 'stubs' outwards of the outer CVs to keep the wheels on and ABS working. People have done this, but I'm not sure if there are any other implications.
Hopefully a £15 blanking plate, an hour or 2 of your time and some oil for the IRD and you'll be back on the road.