ALL wills are 'payable' on death. sort of. you don't have to have a will if the existing state laws for 'intestate decedent' are acceptable to you. will does NOT apply to anything that has a separate 'transfer/pay on death' beneficiary designated. this typically includes life insurance, 401(k) accounts and IRAs. any assets of a living trust would be in this category too, but such trusts are not so common. try googling 'basic estate planning for singles'
Yes, you should have a basic will. Your 401k account contains a beneficiary designation; however, your other assets will fall under your estate. How near or far you live from family is irrelevant.
A will is payable on death, you don't need to make it that way. Yes, it is a good idea to decide in advance to whom your property should be distributed to.
Can't hurt. The moment you have more in assets than debts, a will just make sense.
A will is always a good idea. If you die intestate then the state and courts will decide who gets what.
You should look into a irrevocable trust as well.
only if you have no will