I can partly answer a few of your questions...First, yes AF can be erratic after the m/c. I was told that some women take a few cycles to get back to normal, some get back to normal right away. Sometimes it is lighter, sometimes it is way more heavy. AF is a wicked, wicked 'friend' and just like a box of chocolates, you never know what you are gonna get!
As for the re-freezing embies. I am SURE that they freeze the embryos separately. It would seem stupid not to. That way you can decide on how many to thaw and transfer. In cell culture, when you freeze mammalian or bacterial cells, you usually place them in a freezing medium such as glycerol or DMSO (dimethyl sulfoxide- stinky chemical). Anyway, depending on the cell type, you either flash freeze them (quickly drop them in liquid nitrogen, -196 C) like I do competent bacterial cells, place them directly at -70 C, for transformed bacterial cells. Or do a step-wise freezing from putting the cells in the cyro-protectant solution on ice, then transferring the cells to a -20 C for 1 hour, then a -70 C freezer overnight, then eventually into liquid nitrogen (-196 C). This is done with mammalian cells. To thaw mammalian cells, you normally warm them quickly from the deep freeze to 37 C in a water bath, then put them in growth medium. Depending on the cell line, the cells can start to grow anywhere from a day to several days. By mammalian cells, I mean anything from mouse cells, dog cells, hamster cells and many different types of human cells- most from some sort of cancer. With these cell types, you generally let the cells divide for a round or 2, then can refreeze them. When those are thawed, many survive. But here we are taking about 1-10 million cells. The culture as a whole can afford to take major hits (many cells dying).
So, I assume (although I really don't know the procedure for embies so here I am speculating) that they will thaw your embryos and let them grow in some sort of growth medium (chock full of nutrients such as trace metals, amino acids, etc) until they show signs of life-dividing. I found an article where they reported a case of a successful pregnancy after refreezing/thawing an embryo.
Successful pregnancy following replacement of embryos previously refrozen at blastocyst stage: Case report -- Farhat et al. 16 (2): 337 -- Human Reproduction
But still, I don't think they would thaw all of them unless you wanted to implant all, or if the intial ones didn't make it. But I hope all of them do! And I truly believe that the skill of the person handling the embabies plays a major role. Just like in any lab.
No, every embryo will be different...different traits, different genes, just like 2 sisters (non identical) or 2 brothers or a brother and a sisters. Maybe 1 might have fragmented chromosomes. Maybe they all have perfectly normal chromosomes. Your m/c should not reflect the outcome of any of your snowbabies. The only way it could is if your m/c was from some sort of genetic issue that was passed down to some or all of the other embryos. But that is HIGHLY unlikely.
As for the number of cycles you have to wait, I am willing to guess that your RE will say you need to make sure you have a normal cycle (or 2) and after your uterus has healed from the D&C. Depending on the person, it could take 2-3 cycles. Some women are ready to go the next cycle. And some women have any easier time conceiving after the D&C - it does clear out your uterus, making it ready for future implantation...
As for your odds, I really really want your FET to work so I am going to say 100%. Cause I really really want it.
Okay, now that I have bored you...