HJC helmets are not bad, just aslong as there not the base 99 special helmets. The top of the line HJC is pretty decent.

Mesh does tear apart in a crash, but it is a lot better then no gear. Plus with the back support will help a lot. But in the end leather is always the best, they do make perforated leather jackets and IMO its pretty close to wearing a mesh jacket.

Buying gear that fits properly is another important thing. You can have all the padding in the world, but if your jackets a size up to big it can be very bad. For instance when you land padding will be in the wrong spots, then the leather folds and then the abrasion to the jacket gets worst thats when the leather starts to split open.

Another thing to consider, is how you crash and land. Once you fall down, you want to make sure your on your back. With your arms spread wide, and legs almost in a walking position. Just relax and do not panic, let the slide completely finish. When you start to tumble and roll thats when the bones start to break.