The low is punishable and is only a 50/50 off of the 14 string. Thing is, your not gonna be able to land this string often as standing 1 whiff on crouching opponents who are blocking. It can restand opponents but it's not very useful due to the recovery and knockback on opponents.
Up hammer is a lot safer and is only jab punishable. However there is no reason to use it as your strings all start high which is risky to use and those strings are also safer on block if you don't cancel into a special.
So basically both are worthless. Just ignore them for the most part.