Let me see in an ideal world..
Choosing a cat - Well in an ideal world I'd live in a grand rambling house in the country. I would make a kitties house, a sanctuary for stray/unwanted cats but without the cages. They could just roam around as they pleased. Throw in some sphynx kittens too (not literally please they are delicate), it's always been a mini dream of mine to have a sphynx or two
Insurance - Hmm well seeing as there would be say maybe 14 cats in this rambling house (10 rescues,2 sphynx and of course Nefertiti and Tiramisu). Oh by the way I forgot to mention I wouldn't work my rescue babies would be my job. Now insurance hmm. I think I wouldn't bother but I'd have a big savings account for all the cats instead.
Vaccination - Yep defo keep with those vaccinations. Better safe than sorry IMO.
Food - I'd have a big box freezer, seeing as I'd have my big rambling old house it would be in a private utility room. All the fur babies would get raw fed. lol I guess feeding 12 cats raw would be a days work in itself. But yep ideally every one would get the raw food !!
Indoor/Outdoors - Well the big rambling country house would be set in beautiful grounds. The grounds would have a very high cat proof (if there honestly is such a thing) fence! So they could go out but not go so far away they would be lost. I would also grow cat mint and cat nip so they could roll around it like giddy kippers. Also there would be a stream full of fish
(well actually that might be a bit unethical but oh they would love that).
Toys - Well there would be cat trees in just about every room and tons of toys. There would be wall shelves and also I would create a network running throughout the house just for the cats..
The Cat House 
And yep they would be spoilt totally rotten all of them
Also I think queen Nefertiti should have her own thrown with a smaller one beside it for little Tiramisu (though she won't always be so little!!)
Arh yes and I will employ a butler especially for my cats and he will walk around with a tray of smoked salmon and little dishes of double cream for every one.