The effect of greater sustenance and the like from the supplication that the Imam (peace be upon him) taught shall occur with the permission of Almighty Allah. Other supplications are general invocations to Almighty Allah and are good at all occasions and times.
It is recommended to recite the Holy Quran even for those who do not understand its meanings. Reciting with contemplation and understanding is definitely better, but this does not mean that reciting without it has no value.
If the said device becomes najis, then it cannot be made tahir without using water. You can use the device even if it is najis. If your hand is dry, then it does not become najis when it touches it.
