Unless she is an absolute diamond that would be valued very highly - leave breeding to the professionals with fantastic bloodlines who are happy to spend good money on top quality stallions.
There are plenty of good broodmares with proven show records. IMO you could end up breeding a mediocre horse that will sell for very little, probably not paying it's way by the time it is sold.
This, absolutely. I HATE that (in general) mares aren't held nearly to the same standards that stallions are when it comes to breeding. I've seen on multiple forums (this and others) and in real life a similar situation... "My mare is too much for me/lame/etc" and it's often advised that she be used for a broodmare instead.
Very poor logic IMO and I usually hold my tongue, but since the question is being asked I think it applies 100% in this situation.
Things like bucking and colicing do happen in horses. The vast majority of horses will colic under the wrong circumstances, and same with bucking. A problem bucker or colicy horse? No way would I consider them breeding worthy. The ONLY way I'd consider a chronic bucker to be worthy of breeding is if the bucking is caused by pain from an injury not related to the horse's conformation.
Looking at her picture I would also say there are a number of things about her conformation that I wouldn't want to pass down.
My guess is that you'd produce a mediocre foal that isn't marketable, and you'll still have a mare you can't handle when the foal is gone. Just like Maple said, I think it's a very good idea to pass on breeding this mare. Spend the money you would have spent doing a proper breeding (it can get pricey) and hire a trainer. Otherwise, disclose the horse's issues and find her a more suitable home.