You should definitely write about both issues and you'll likely get something.
FYI, under the circumstances (especially since you were willing to pay for your own hotel) you should have called reservations and asked them to rebook you for the next day. Sounds like that's what happened anyway but in a case like that where your booked flight is cancelled or significantly delayed you can usually get satisfaction over the phone. The airport agent probably just didn't want to have to deal with taking the time to rebook you because she was busy.
As for the large woman next to you..most unfortunate..especially because the person who was supposed to sit there gave up his exit row seat! That's some bad luck... could this woman sit in the seat with the arm rest fully lowered? That is generally UA's requirement..if the answer is no then she should have been required to buy an extra seat. Also, did she need a seatbelt extender? I don't believe extenders are allowed in the exit row.
Finally..when posting, please type out the city names rather than just using airport codes when talking about obscure airports. I have no idea where SMX and SBP are because I didn't want to take the time to look them up.. just assuming they're in southern Cal.