Cycling questions

So I'm starting up a 29 gallon saltwater tank and I'm in need of some advice. Before I'm attacked. Everything I've done thus far was advice from my father on how to cycle a tank because that's how they did things back then. I started with two damsels(blue and domino) and some gravel and some dry rock and decorations. I know now that's not how to cycle but there's no going back nearly 4 weeks later. They actually haven't shown any signs of distress at all. The ammonia went up one week in and went down to 0 two weekends ago, now the nitrite has been over 5 ppm for about a week. I've did a few water changes and added plenty of Seachem prime and they're still doing good. It appears they will make it through the cycle with no reservations and I expect my nitrite to drop any day now. My question is, do I need to get rid of the damsels, if so how? I can't take them back as I purchased them from petco since it is the only store close by. I plan on purchasing a Valentino puffer and coral beauty and I don't want them getting sick or injured by the damsels. My dad has two damsels in his tank that don't appear to be aggressive and mine have been fine with each other but I don't want to take the risk on $70 worth of fish compared to $10. Again, don't bite my head off for the decision to do a fish cycle as it wasn't my idea but just want some help to finish things out the right way. Thanks in advance!