Nose wheel wear is a lot less than the mains. If the side walls are not cracking and there is tread remaining then carry on. If it makes you happier to change the tire (& tube?) based on age then go ahead, its your airplane, write the maintenance schedule as you see fit.
Yes, nosewheel flats are no fun, but that is often caused by taxiing too fast on bumpy taxiways with an underinflated wheel.