buckeyecapsfan19

If by dying, you mean players are moving to other platforms, then yes, I think this game is dying. Just go to one of the sandbox worlds. When some clown can go all-economy with the largest widebodies in the game and drop 100x+ a week on routes, how many people are going to put up with that? I know, it's the sandboxes, but it is (and has) happening in other worlds.

Aircraft age is fine as long as it is under 20. You can usually even go up to 30 years. Therefore you can probably wait for ATR-72-600s or keep the F-70s until the world ends.

Replace like for like, or as close to it as possible. For an F-70, go for an E175. Comparable pax load, the Embraer has a smaller range, which shouldn't be an issue unless you're operating 1,800 mile long routes with the Fokker. I usually replace planes when they reach 20 years in service. I know for my fleet of MD-83, 717, and F100, I'd replace with a mix of 738 and Embraer 195. 757 is tricky, there's a reason why the IRL majors are keeping 25-year-old planes around.