Wow. That's a pretty heavy load for a cycle! However, the old rule of thumb used to be that if they survive the ammonia, they'll survive the nitrite. We didn't even used to have nitrite test kits.
The percs and damsels are tough, so I wouldn't worry too much about them. Don't know about the blue tang. I would have thought that the star and shrimp wouldn't have lived, but if everybody has made it this far, I guess I'd be tempted to sit it out. From the numbers, it looks like you're about five weeks into the cycle? If so, you don't have far to go. Water changes might be a good idea.
At least you'll know you have some tough critters when you get through this!
Don't worry about the nitrates. There are a lot of silly numbers floating around recommending various nitrate levels. You'll want to pay some attention to it when things settle down, because your star and shrimp will appreciate it, but do some research first. LOTS of different opinions on this one.
As for test kits, they're a little like hydrometers. I have three hydrometers and they show 1.019, 1.025 and 1.022 on the same sample. Go figure. Most folks are a little challenged by the various color schemes and reference charts used by the test kits. I'm color blind, so I have my wife read them!
Good luck!