But once your child get in their head that you spank them for things they do wrong, when you do something wrong they will feel to do the same thing to you...

Exactly! Once kids grow up they will just laugh at the fact that they are getting hit.

Some kids don't learn by spanking them..So why waste your time on that, when you can always take something valuable away from them.

Obviously there is an appropriate age to stop, who wants their kid sucking on them before them heading to school? I would say if your child still wants breast milk, stop the breastfeeding and start pumping and feed them by bottle.