Indeed. And that is the crux of the situation. We would have to have the knowledge -- and, possibly more importantly -- we would have to know we had the knowledge to do it, which may never truly happen. I think, though, that at some point we will have the knowledge, and the certainty that we had the knowledge would be so high that we could safely do it. Do we now? Who knows. How many trees, creatures, etc. have we destroyed so far without any observable repercussions? Probably a shit ton, and we can reintroduce artificially if needed in instances where we have the necessary samples, so we are probably good. This is more of a long-term thought strategy; not that doing some of these things might not fuck us for 50 years or something, but that I think we have options to rectify in the long-term (if needed).
As for God, I suppose the argument would go either way. I believe that God's intent is simply whatever occurs, regardless of whatever occurs, because we couldn't possibly know the intent under any circumstance (barring, say, God telling us). I think it would be hubris to presume to know that God's intent was for us to not do these things as much as it would be hubris to presume to know God's intent was for us to do these things.
So, I'll opt for the YOLO (presumably :O) option.