Talk

I like them to match. Looks neater.

No, I prefer shabby chic. Neat is boring, lol

Yes, is the law

our doors don't even match

yes.

And need not be at all expensive.

However if you want knobs not handles, your latches need to be at least 3", preferably more, or you will bang your knuckles. A Victorian or Edwardian house suits knobs and a 5" or 6" backset.

Not necessarily. It is preferable but sometimes in period houses you would have 3 types of knob.
An ornate one for the formal rooms off the main hall - drawing room, dining room, sitting room
A slightly less ornate one for the family bedrooms
A plain brass one for the service rooms

Thanks I am clearly vair posh as I was actually thinking of an arrangement much as wonkylegs describes in my not very big 'ouse.

As long as they are not a mixture of knobs and handles I suppose not. Personally I like the matching look (even the cupboard handles in my hallway are smaller versions of the door handles) <loser>