the hold the weight perfectly fine for driving to work and back which is all they’re meant for.
do you have any idea how a tire is put onto a rim? if you don’t clean the mating surface of the rim it will probably leak. i’ll blame the leak on a lazy ass installer.
the wheel weights have nothing to do with a tire leaking, i’ve never seen a wheel weight cause a tire to leak. ( i used to work at a mechanic shop, i’ve installed a lot of tires)