The beneficiaries can decide to do whatever they wish with their inheritance, so as long as the other two beneficiaries (your brother and sister) won't try and dispute what you have done at a later date, you can come to your own arrangement that works for you. The only problem comes when you eventually sell the house, your brother and sister need to be sure that they will receive their share, and how it is willed from your estate because you are the legal owner of it. I.e. if you die - i suppose you could leave it to your spouse or one of your children but grant your brother and sister a life estate in the property. I would just make sure you are all clear on those types of things before you go ahead without making this entirely legitimate.
And yes since its a transfer from deceased to executor it would be free of stamp duty. With respect to capital gains tax on deceased estates, any capital gain or loss made on an asset is disregarded if, when the deceased dies, their property passes either to their legal personal representative or to a beneficiary or from their legal personal representative to a beneficiary.