I can answer your last question. About 25% of those with a parent with bipolar will develop bipolar.

My father is nearly certainly bipolar, as was my maternal grandmother. I have cousins with bipolar as well. With the history on both sides I figure I didn't have a chance, or at least there wasn't really a chance that one of my siblings or I would have it.

It sounds like your mom may have had some issues but it's hard to know what exactly (other can look similar to bipolar at times). It's hard to know via computer and we're not able to diagnose anyway. But it is not easy to grow up with someone who is inconsistent so I'm sorry you had to deal with that.