Mesh jackets are the next best thing to leather for protection, if you think its to hot to wear leather, you better put on the mesh. Proper safety says wear boots/shoes that cover your ankles, i just wear whatever. Alpinestar and Joe Rocket offer some nice alternatives to riding boots.
More on the mesh jacket, it will hold up just fine in a crash however, after 1 crash, trash it. The mistake made by most concerning jackets is fitment. You want the least amount of slack in a jacket as possible. If you are wearing a loose jacket and crash, it most likely will slide up on you putting your skin at the streets mercy.