As for correct cable wiring, see USB high-speed on wikipedia. Ho ever, as joerg_rw said, sharp edges are also a problem.

It may work for reflashing, but I would not use it daily as USB 2.0 workaround. Also, be extremely careful with any possible static etc. Remember that "test pads" are connected directly to chip, without any protection, so You're able to kill device for good using this without required care.

Also, even if Your "proper" port pads were destroyed, You can still connect wires to elements "after" USB connector pads. Just read this whole thread, picture of where every path "end" (going from USB port pad) is there.