Easy stuff first; DH - Dear Husband, DD - Dear Daughter, DS - Dear Son, etc. I think there is a thread somewhere that explains most of the common acronyms.
Pumping; The amount you pump does not reflect on your milk supply. Babies are <b>far</b> more efficent at getting at that milk than any pump. I was never able to get more than 4 ounces in a day! But I've been nursing my daughter for over two years now (well, 2yrs and 1 day
Nursing a lot; DD nursed every 45 minutes for 5 months or so. She still nurses quite frequently. For your daughter to nurse every 2 hours sounds fine.
Starting solids; This is a tricky one. Some people have food allergies in their families, so want to postpone starting solids as long as possible. I know my daughter didn't express much interest until she was about 8 months. And I don't know why sweet potatoes would be a problem. They are rich in vitamins, taste good, and are generally non-allergenic. So, if your daughter is exhibiting the signs that she is ready to start solids, I would say, go for it.
Follow your instincts. If you think she's ready, she probably is. You know your child better than anyone else.
Pooping; It does seem to take a while for them to get a really good poop started when they begin solids.
I think DD went for several days when we started her.
Other people's comments; If your daughter's healthy, thriving, your doctor's aren't concerned, that's what's important. My general theory is that people are idiots and don't think before saying something.
: Everyone has an opinion, it seems. And everyone also seems to be experts on everything.
I hope this answers some of your questions! Good Luck!