I actually just changed the battery on my G5 instead of buying a new phone, and it is working great again.
Not being able to change the battery is planned obsolescence, that is all it ever was.
Not with sealed ports. I never trusted the S5 water proofing because of things like the battery cover and unsealed ports. Oh, and the charging cover broke off both of my wife's S5s...
I recently dropped my Galaxy S5 [with a case and glass protector] into the toilet (gross). It was probably submerged for a full 2 seconds. Absolutely no side effects what-so-ever. I even gave it a full rinse in the sink afterwards.