The red flags always show up when they decide I'm going to hear all about their kids, especially early on in the friendship, and honestly, I have no kids, what on earth what I have to relate to in that regards? Moving on from there, something deep inside of me, moves me to not consider an annulment to be a license to remarry. It just rubs me the wrong way when I hear in almost all cases, the original marriage vows are what are being broken. These are stemmed in almost all cases because the couple decided to forgoe the traditional manner of courting, they just jump right in, and wonder why things went wrong.. If you really get to know that person, you will know their friends, relatives, their reputation, and it will be no mystery along what to expect down the road.
Just my two cents, for what it's worth, but it's why I will not date anybody who is divorced, annulled, or otherwise, especially if they have children. I want my own, and i am not raising someone else s kids, for every time they look at them, they are reminded of what and who they had in the past, there never is clear separation in that regards.
As for a "clear separation", well, what if the person is widowed? Would you want them to never remember their deceased spouse when they look at their children? Why? Not every relationship i life is made up of the perfect nuclear family where no one ever dies, or faces abandonment, annullment, divorce perhaps against their will, etc, or where there are not children involved. I can understand having never been married wanting your own kids, etc, but unless you marry a woman at least ten years younger, her childbearing capacities will begin to be limited quite soon--the ability to conceive naturally drops sharply after age 35, so that may be something to consider.