This touches on Epistemology. My view is in line with the scientific understanding that objective reality exists independent of our sensations. That if life ceased to exist, reality remains. I do not subscribe to the salesperson's mantra that perception is reality, if you perceive yourself to be the Jesus Christ, I have bad news to tell you. I think objective reality can be understood through sensations and reason.
I completely agree with this very important point. A tree that falls in the forest with no one around to hear it does indeed make a sound. I think the issue is more that if one is coming up with a list of statements that are intended to be helpful philosophically, then it makes sense to address the point that is in philosophical contention, which in this case is that even though the vibrations created by the falling tree are of a particular "atomic" nature, different people are going to perceive those vibrations, or fail to perceive them, in different ways. So what we are trying to point out is that there are definitely things going on regardless of our perception of them, but at the same our own personal knowledge of those events arises through our perceptions.
Possibly the whole issue is being obscured, or not revealed clearly enough, by affixing the terms "objective" or "subjective" to "reality," without really stating what "objective" and "subjective" are intended to mean.
I agree with most of the above, though there's also quantum effects that new research, I don't really yet understand fully, suggests there may be more to say on this.I think this is no longer to be considered a philosophical matter since it's now, I think for sometime already, a scientific matter.
Definitely the issues develop over time as we gain new instruments and new observations to consider. However I suspect that there is always going to be a philosophic aspect to this, as the developments of science never stand still, and new discoveries are made. So we are probably always going to be confronted with issues of what attitude to take toward "ultimate questions" which seem to be a moving target against new scientific discoveries. I suspect that Epicurus would say that this ultimate issue is much the same as what he himself confronted in considering the claims of the mathematicians of his own day.