Assuming the person who made the will is still alive, you could ask them what their intention is as to who is to be responsible for the bills in the two years?
And they can update the will to reflect that.
On the other matters, the stay in the house son can always voluntarily opt out? And Probate can go ahead when the Testator dies?
Otherwise, Probate can commence on the death of the testator. If the house is to be sold, why bother putting the house title in all of the beneficiaries' names?
And beware of CGT between Probate and the sale.
This all sounds like something a family meeting might assist with? Who wants to do what?
And if a family meeting won't work for whatever reason, I suggest a solicitor's involvement early in the Probate process.
mf