Re: A debt is still a debt.
It's the definition of estate that is the only source of confusion. Most people don't understand what it means. In effect, I haven't "died", I'm still around in the form of my estate. Pretend I'm infirm, and so someone is nominated to take care of my life. That's the estate, and the "executor" of the estate. They won't be paying my bills from their pocket, ever, but they will handle what money and assets I still have left and paying off debts on my behalf. My personal debts, however, do NOT become their personal debts.
Also, if I die leaving a millions pounds of debt, but only half a million pounds to my family, that half-a-million will never go to my family. If it does, it will be pursued and reclaimed. It doesn't matter what my will says that's not my money to bequeath. (This applies to a lot more in wills than you might think - if you attach ANY condition to a sum of money or asset in a will, for example "only if he gets good grades" or "only if he doesn't marry that woman", then the person who would get the money can sue the estate for it, no questions asked, no matter what they have done. Always check with a lawyer.)
So they can pursue the estate, and the person who managed the estate, but they cannot expect even that person to pay them money from their own pocket. It comes from the estate. However, if the executor - or anyone else - was left even a pound in the will, then that pound can be taken from them as it's still technically "mine" and thus still technically owed to whoever I owed it to. Otherwise, "dying" would be a fabulous way to legitimise an awful lot of criminally-obtained money and assets that don't belong to you.
The difficulty then arises from shared properties, etc. My estate might include only half a house (half of a family home, for example). The companies are quite right to pursue the value of that half of the house - even if it means the other owner needing to sell it, or take on half the debt themselves so that they own all the house. Similar things happen with longer term contracts, e.g. cars, phones, etc.
In terms of contracts, technically I might have breached contract, and that might incur a fee on myself, which - because I'm dead - is a debt on the account. However, a late payment fee when you're dead is a bit overzealous. It has to be said that payments don't get much more "late" than that, but there's no way for me to reasonably fulfil that part of the contract upon my death. The fee, therefore, is probably not pursuable. However, my estate would still need to return any phone tied to the contract, outstanding monies, etc. The executors of my estate can't just not pay my bills if there's even a penny left in my estate.
However, unlike many people think, those debts CANNOT be transferred onto other people directly, even the executor, unless there's some kind of major mismanagement of the estate (i.e. fiddling!). If I owe £100, my dad isn't legally required to pay it for me now, and the same is true if either of us dies. The problems stems when people are too keen to distribute the assets and not the debts, because then that involves clawing back inherited assets from people and redistributing them.
Oh, and be careful who you appoint as executor. I know of one person (legally trained) who has been appointed "joint executor" with her arch nemesis (not legally trained) from the other side of the family. That's just ASKING for trouble.