With Eps 3 and 4... yeah, I did my best, but wasn't entirely certain what direction to go with some of it. I also didn't know what precisely were the objections to Ep 3 anyway, so I don't know whether I even addressed them. But! I'm glad you think progress was made.
In Ep. 4, I suggested the Sindar offer knowledge of how to coppice wood so the trees will actually grow back. The Dwarves have been clear-cutting everything indiscriminately, and probably damaging the soil and all kinds of stuff, through ignorance. So the forests they've already cut are not growing back fast enough for their needs. They're not eager to expand north into the tundra, and there's limited room to expand south with the Bay of Belfalas there, so they're spreadying east and west. Well, too far east is Longbeard territory, so they're expanding west.
The Sindar, while they do use wood, are careful to coppice trees, cutting only those species that can be coppiced and doing it in the way that lets the trees grow back faster from their own stumps and roots. If the Dwarves learn this method and cut wood sustainably from now on, the lands east of Gelion and east of the Blue Mountains will fill their needs for wood without never-ending, industrial-European-style expansion.
Another reason is... well there are these huge scary walking tree-people that effortlessly killed Gamil Brog and tore apart his stone forge (and maybe a section of road?) like it was made of bread.
They're pissed off by tree-cutting to the point that they aren't even entirely comfortable with coppicing. The Dwarves aren't much scared of war with the Grey-elves... but they're not eager for unnecessary war with the Ents.