FIV cat in multi-cat home

What are some of your experiences with multi-cat home with one cat FIV positive? I have three cats (Scuba, Hoover, and Rugby): one (Rugby)was recently tested FIV positive...they are all indoor cats and each came to me in different circumstances so how Rugby got infected is unclear. But regardless, I am keeping them together (as oppose to putting Rugby to a FIV shelter (or other options) because I understand that the chance of the virus transmission is low among friendly cats, and I just can not abandon Rugby just because he is sick--he is happy with Scuba and Hoover. I have also decided against testing Scuba and Hoover because I decided that knowing either way would not change anything in terms of them staying together--I think it's unfair to Rugby to be sent away. Is this unfair to Scuba and Hoover who are not (supposedly) infected to live with Rugby?

So, could someone share a similar experience about transmission? About longevity? etc.

The people I know with FIV cats that choose to keep them, have always sequestered the infected cat away from the others in the home. There is an organization that will only adopt out FIV and FeLV cats to homes- if you are interested I can scare up the link-

My girl got FIV sometime before the age of 5 I believe. She used to be an indoor/outdoor cat. Once she tested positive, she became indoor only. She lived with 5 different cats after that, never infected a single one, and I recently put her to sleep because of a tumor in her intestines. She lived a long happy life. All cats have to be neutered to reduce the fighting, and the infected cat has to be kept healthy and live stress free (as though a cat's life is anything but right?)

My 17 year old Fred is FIV+. I do not know how long he has been infected, we have known for about 7 years. He is a very loving boy, not a biter, and has never infected any of the others. I have them tested periodically.
He has had a few siezures, and has 2 non healing lesions, but he vet says it could just be from being so old, and having sustained a severe head injury 12 years ago. He has a little arthritis, and does not play as much as he once did, but he is still a sweet, loving kitty. The others have stared to become a little more gentle with him lately, like they know grandpa Fred is getting old.

Since FIV is not transmitted from casual contact there should be no problem as long as he is not going around biting the other cats. About 50% of cats infected with FIV never show symptoms of the disease and live a long happy life. Minimizing stress is the main thing I found when I did a search on FIV.