Nods.. The stock needle gives most people the same issues. A few alternatives if you have a read in the jetting section.
The gas caps leak. Its not to do with the threads but to do with the actual rubber seal inside the cap. If you have a look you'll notice its probably started to shrink, distort, and harden. I've binned mine and just run it plastic on plastic. It seals better than the stocker. I also have a brand new cap in the spares bin, but don't see the point. I've been through a 2 caps already. Someone else was selling a seal for them, or you can hit the rubber store and make your own. Just make sure the rubber will hold up in fuel.
The handling sounds just like what you'd expect from a GG
The brake cooler can be replaced by a normal nissin mc cap. My 2010 EC300R didn't have the cheesecooler option and I have never shredded my boots or cooked the rear brakes. Make sure the line doesn't rub against the casing where it doubles back too. I had mine wear a nice groove into it.