EDIT: just looked at your album again and I am positive that your black and white is an Ocellaris. 100% would bet my favorite coral mother colony on it....search darwin ocellaris on the web.
To be fair, it's really hard to tell exactly how many spines they have. Even with a great photo or close up live view. And like most rules, the spine count is a general rule, not a law. If you look closely at the pics I posted, the Ocellaris pic looks to have 10 spines, but that's because the last one is so tiny that without having a great deal of experience, it is very difficult to see. Then check out the last pic of the small true perc. In that pic it looks like their are 9 spines, when in fact their are 10. I guarantee you that your black and white is an Ocellaris though. No question. This confusion is very common in this hobby as the words Ocellaris and Percula are the scientific names of two distinct species of Amphiprion (anenome fish...clownfish). Ocellaris and Percula are very closely related species and can be difficult to distinguish. The problem comes in the way they are marketed. In most LFS you will find clowns marketed by common names like percs, falsies, occs, false percs, black percs, etc.... I know from experience...sometimes very painfull experience... that many LFS owners and employees can't tell the difference between the two themselves. It is common knowledge that the Darwin black and white is an Ocellaris, and does not look even remotely similar to the most melanistic percula (blackest perc) I've ever seen, so for stores to be selling those as black percs seems odd. Actually it almost seems a bit dis-honest. Truley melanstic percs are rare, and bring a premium price. They are generally referred to as Onyx clowns. To me, these type of distinctions are meaningful because I do breed clowns, but for most hobbyists, I would say whether Perc or Occ, either way, you chose a great clown. Both species are a lot of fun and have tons of personality. They won't get too big for your tank, They won't get too aggressive (unless they do spawn in which case they will get very agro in their territory) and they are hardy. If you really want to know take the best pic you can of each and post them in the anenomes and clownfish forum. Ask for an ID. You will learn a lot...
As for behaviorial differences...every clown is a little different from every other clown. Nothing substantial along species lines though in my experience.
As for breeding, Occs and Percs have been known to inter-bred and have done so for many different people. With your fish being as old as they are, judging by your size eztimates, and bonded nicelyl, I wouldn't be surprised if they did mate. They might well be affected by the wrasse and the damsel. If you really want to breed them, the best plan is to put them in their own bare bottom tank with no distractions. This is very boring though, and I don't get the sense that you're looking to go full on into breeding. Correct me if I'm wrong on that because if that's what you want to do, I can steer you to some threads here on RC that will give you a crash course. If you just want to enjoy your tank and hopefully someday come home and find a nice nest of bright orange clown eggs, then patience and plentifull feedings are the key.
Edit #2 as far as getting your damsel out, search fish trap here on RC a lot of people use a 2 liter bottle fashioned into a makeshift trap. It works well, but I don't have one lying around to take a pic of.
-Mitch