2) Were the trees killed made susceptible to the beetle because of heat stress, possibly caused by human driven climate change? (this is the case for some large scale infestations)

Overall, the point is; yes, where imbalances in nature are triggered by natural causes, there is no issue with that (earthquake, hurricane, long term climate oscillation).

Where imbalances in nature are triggered by humans, (IMHO) we should quite naturally regard that as a negative since a) we are intelligent enough to find ways of avoiding environmental degradation and b) Environmental degradation has both consequences to other forms of life as well as other humans.

I guess you're playing devils advocate here, but you're hardly adding to the conversation.