Nature's Balance in Resources

[Pyrodrew]

I've noticed some changes to resource placement when new resources are added. I've noticed by adding Hardwood/Timber to forests it seems to scare some deer out.

Since Bonus Resources do not have an Appearance/Disappearance Rate it appears new Bonus Resources create more total Bonus Resources rather than any balance.

If a Strategic Resource has no Strategic Use, will the AI still value/trade it?