For Filipino moms and dads, in this day and age, do you still practice the use of "po" and "opo" and teach your kids to do the same?

Yes, we still do. The funny thing is even when my daughter speaks in English she doesn't forget her "po" and "opo" . There was a time when a grand aunt told her not to say "po" and "opo" anymore. I was surprised at my daughter's reply. She said, "La (name of the grand aunt), Daddy and Mommy told me to always say "po" and "opo" to older people." That was a proud-mommy moment for me.