On the battery thing, that might depend how much games are run on it. We hand down devices, and replace the battery if its life is below the 70% mark so to somewhat refresh the device. The SE 2nd gen we handed down already had two battery replacements at this point and I'll probably ask for a third before it falls off the support list.
On third party repairs...it's sure getting better, hopefully in other regions as well.
Also, 3 year battery life is much more realistic to me than 1.5 years, but that's just personal experience.