I agree that marrying or dating a single mom is a horrible idea for exclusive pedophiles. If you're attracted to women too it could work but it's still probably a bad idea.
#3 - I would say volunteer work is a lot better than employment with kids, in general. Teaching, for example, is very stressful and you can burn out pretty quickly doing that. If you have no criminal record (involving kids, at least) it's easy to find volunteer work that's pretty laid-back.
#5 - I've read a few cases of single men adopting girls on online forums but it seems extremely rare. Adopting from the state is not expensive at all - foreign adoptions are expensive, like mid-five figures. There's a lot of discrimination and I think your chances of success would be quite low - on top of the fact that it's simply hard to find healthy, young children that are available for adoption.
Also, I think the average pedo would make a better parent than the average non. I don't see how having a romantic interest would get in the way of being a good parent - instead I think this would lead the person to be an even better parent.
Shit like #6 is why if you're interested in things like this, seek out non-English-speaking countries. Something like that is like night and day - having the cops harassing you and your neighbors suspicious of you versus meeting friendly children and having neighbors smile at you.