Unless your home is traditional what you have done is fine.

Looks great!

You could have used wider trim but this is fine. Probably wider than the old trim was anyway.

Re: Putting PVC in there to protect against any flooding mishaps - Looks like you still have drywall, which means a tear-out if a flood occurs. Doesn't make sense.

@HU-867564120 probably fair .... the old trim was seriously warped.. hopefully this will hold better and may even be reused in case of light flooding or very little water...not sure the prize difference is humungous anyways. I was just interested to hear the aesthetics

So long as the drywall is above the floor--1/2" gap is recommended--drywall will survive a minor flood event.