Re:
Wouldn't thin them as they have collectively grown with and protected each other for decades. Take some out and they start to get mis-shapen, exposed and more susceptible to failure in high winds. I have similar problem, fewer trees, but way overgrown in current domestic situation, houses nearby etc, mix of spruce and larch and don't want to take them down, but sometimes needs must when pruning/reduction not an option.
Undecided :|