I am sorry, I have not read the whole long thread and don't have time to today, but I wanted to give you my perspective.
I am one of those people who always come onto the threads of women asking "is 44 too old?" etc, and get annoyed with people saying things like "OMG you'll have a teenage when you're in your 60's!" and "you'll be so knackered!". I have one DS, he was born when I was nearly 46. He was planned, as in we wanted to get pregnant, although if my life had worked out differently I would ideally have had a child younger (long first marriage, divorce, then unwise relationship, multiple miscarriages etc).
I am now 62, he is 16 and I am not "knackered". I went back to work when he was three months old and have continued to work full-time ever since. Not got one foot in the grave quite yet!
So, I would be the first to speak against that idea that older women will inevitably be anxious, exhausted, physically deteriorating, snappy, worn out etc etc etc once they get to about 50 (or "peri" as people on here like to call it). Some may and some may not. But even I, and I would like to say this kindly, would say that I think 53 is too old for a baby. After we had lost three babies to miscarriages we decided to give it one more shot, until the end of that year (this was in the August when I turned 45) and then call it a day. Got pregnant again in the October and this time it stayed. (All conceptions were natural and we had already decided some time before that we would not go down the route of IVF).
That's my thoughts. But in the end it's your decision and if after having really thought, researched, and examined your emotions and motives fully, you decide to give it a try, then that is no-one else's business.