I wouldn't worry about spit up. My son literally spewed spit up all. the. time. and it was really gross, but he never choked on spit up sleeping or awake. Spit up can be totally normal, and is not a concern unless there is pain accompanying the spit up.
If your baby is feeding more frequently today and having normal looking poops, then I think that is a good sign that she needs to be nursing at least that frequently. Again, the spit up does not indicate she is over eating; it really means nothing at all. The frequent poops mean nothing as well. My son would poop every diaper for several days in a row, and it was never an issue.
You cannot overfeed when you are breastfeeding. Our pediatrician told me this at every. single. visit. - my son spit up huge amounts constantly and was packing on weight like mad. Our pediatrician simply said it's normal, he's healthy and growing, and you can't overfeed as long as you feed at the breast.
It's very normal for such a young baby to need help falling asleep. Your baby is at an age where she is becoming more alert and fighting sleep is very common. Like I said, my son was a TERRIBLE napper. It took forever to get him to sleep, then I was lucky to get 20 minutes of sleep from him. I used to change his diaper first, then nurse him to sleep.
Obviously, you need to do what is going to work best for you, but it really sounds like nursing more frequently is better for your baby despite the spit up. Personally, I prefer to nurse on demand, but if was tied to a routine I would go with the eat-play-eat-sleep routine over the eat-play-sleep, which can bring about serious problems (it's easy to go from an oversupply to an undersupply pretty quickly by spacing feedings through these sorts of routines). I didn't do a routine so I don't have much advice beyond that, but you might want to at least get creative with it in order to fit in more feedings. Also remember that your baby is very young yet and will likely fall into a pattern on her own as she grows.
Again, keep in mind that spit up absolutely does not indicate overeating; it is simply the norm for some babies (mine included). Wearing my baby more upright in a sling or carrier helped a little bit though (although I did get spit up on in the sling/carrier a lot too - I often put a towel between me and my baby because of that). If your daughter seems to be having discomfort from gas (common with OALD), you can bicycle her legs between feedings and give warm baths. Mechanically working on gas is much better for little tummies than spacing feedings.
ETA: And of course excellent wisdom from Mommal, as always. It takes me forever to type on the iPad, and I'm always missing stuff!