Etiquette, Morals and Heart-Softeners

Yes ,you can

No, there is nothing wrong with it at all.

As long as you are the only one drinking from it, it is OK providing that you don’t breathe into it.

This is not allowed because if he leaves the left hand the glass would fall, while if he removes the right hand, he would still be holding it with the left hand which means it is the hand holding the glass.

As long she is giving her advice , this isn’t backbiting as she is seeking advice

This is not the practice of the Prophet salla Allahu alaihi wa sallam nor of his companions. This is not advisable to give a child three names especially that people would mistaken his father’s name through all these names. As for the name Raheeb, this is not a good name as it means “horrible”

As long as she is serious, yes, you can use her voice. But try not to pick someone with a soft and feminine voice as much as possible.

I have never heard such a thing

Yes ,you can.

There is nothing Islamic about this topic to my knowledge. You just have to practice repeating it over and over.