I haven't read the whole thread, but my view is that a little TV isn't going to do any harm.
Certainly TV being on ALL DAY is detrimental IMHO, simply because it is very distracting, and a child who is used to having TV there in the background is likely to find difficulty in concentrating on anything else. Learning to concentrate is, I believe a very important early skill. So TV in this house must be switched off unless we are actually watching a programme.
DS used to watch Teletubbies every weekday morning, from about 3 months old. He wouild sit in his carry-chair (later his playpen) and watch contendely while I got showered and dressed for the day. He was happy, I got 15 mins to myself, it helped maintain some sanity in the house. I don't think it did him any harm. Similarly around teatime programs like Postman Pat or Andy Pandy kept ds occupied while I cooked
When he was a toddler we would often sit together to watch some of the early years schools programs put out by the BBC (such as Watch and NumberTime). These were entertaining and informative, and gave us something to talk about.
I really DONT approve of adults daytime TV being on while little children are around. My mother was VERY miffed that I wouldn't (and still won't) let her watch Neighbours at lunchtime when she comes to stay with us. I think the themes and subjects in it are unsuitable, and small children take in more than many people expect.
Now ds is 7, and of course he watches a bit more. When he comes home school he can be quite tired, and as long as the programmes are suitable, I don't mind. I try to steer him away from cartoons, and he enjoys the stuff shown on UK Documentary such as Planet Earth or Life in the Freezer perfectly well, which educate him too.