Hello.
You don't have to justify how serious you are! Keeping chickens is a fab thing to do - not only do their eggs taste better than any you have probably tried before but they provide endless amusement to saddos like me.
Now, to answer a few of your questions:
You basically need a hen house and an enclosed grazing area. This can be a small run attached to a small house (a la the Eglu) or an independent house situated inside a fenced off area of your garden. It depends really on how much space you have. I would argue that the more grazing space they have, the happier the chooks are and the better the eggs taste especially if they have access to grass. Mine are allowed to roam freely in our spacious garden (we are lucky in that it is walled all the way around) however they will be fenced off into an enclosure once this year's vegetables have been sown (we also don't want chicken poo all over the lawn during the spring and summer!)
My chickens roost inside a wendy house that DH converted into a hen house (he made a couple of nesting boxes and a slatted perch with droppings board underneath.) However if your DH is not much of a handyman you can easily buy houses. Broughton Cottage Arks (google them) are really lovely but also quite expensive. You can usually find quite good bargains on Ebay and in your local Trade It. Eglus look seriously cool but IMHO they are quite small and also very expensive!
It is worth buying a couple of books to start off with. (I read 'starting with chickens' by Katie Thear). Amazon stock loads - it's worth you having a browse through first.
Chckens are not hard work. All you need to do is check every day that they have enough food and water, let them out into the run, collect their eggs and clean them out regularly. I have six and find they need cleaning out every 10-14 days. It's not the loveliest of jobs as they poo more than newborn babies but I think considering they are really easy in every other way it's not much to ask!
Set up costs are reasonably cheap; expect to pay 2-300 for house, run, fencing etc (if in doubt about how fox-proof you garden is and don't underestimate the wily buggers) it's good to buy electric fencing. The chickens themselves cost anything for around a fiver (read up on various breeds and see what you can get locally - I have four various hybrids that cost fifteen each and two silkie pullets that were a snip at a fiver a pop. Food costs around a fiver a month for corn, grit, shell and layer's pellets. It's worth buying a hopper for their water as they drink a lot.
I don't know what your neighbours will think - it depends on whether they like chickens! It's prob best you don't get a rooster as they are really noisy. Make sure they are cleaned out regularly and locate the hen house as far away from your and other's houses. Your neighbours will not thank you if rats start sniffing out their food. Keep feed bins weighted shut and be scrupulous about not leaving food lying around the garden/floor of your shed etc. I suggest if you live in a built up area that you speak to your neighbours first.
No idea about deeds; everyone around me has chickens so I never bothered to check!
HTH