Wow tough questions
This of course an opinion of ''one ''
I have some non natives in my garden They may have some benefits to wildlife but I believe the native plants have more and thus the Better Choice .
The main problem I see with non native is they escape the garden and go wild taking over and displacing the native plants.
I have also read a very convincing article on berries and birds that said non native give the wrong nutrients at the wrong season ...like sugar for winter instead of fat...
not something I had even considered.
Second question
where I live we have a lot of farm fields much of the normal''weeds/wildflowers'' have been destroyed. I think that could also be said where ever people live , with roads, parking lots and weed free lawns...so I feel I am just giving back
Just one woman's thoughts on the matter
Hope you have a great gardening year