As a level 10 f2p player I got about 4k a day on average from incubators. No idea how you managed to only get 2k if the lowest gold/hour rate incubators (3h and 8h) still yield 3k/day even without free speedups, while the others push it a bit higher.
The 4k a day limit is only for blue stops. You can continue to spin green stops for more gold and a tbh few thousand more isn’t too hard if you have a park area near you.
I’m averaging 20-30 cash a day from those stops (mostly green, I admit), another 7-10 cash comes from the free incubator. Let’s say 30 cash a day, that’s another 1500 coins.
You can really get a lot from battles too. It’s hard to keep track of and I don’t know the exact mechanics of gold rewards, but a few thousand a day is definitely not too hard, especially if you claim to be competitive.
Finally, there’s free cash offers that can give you more gold than all of the above. But even without them atm I am making around the same, maybe even more than you.
While grinding to level up those dinos you’ll reach level 18-20 far before you’ll have a maxed team, so most of the grinding will be done at those high levels with higher drops from stops and higher coin limits. So 20-25k coins should be a daily thing for a level 18-20 non-VIP without free cash offers.
As the coin costs for evolving grow faster than DNA requirements, fusing won’t take nearly as much gold as evolving. The ~4 million coins required will take about half a year, nowhere near 2.5. With free cash offers it will be 2-4 months, especially if you’re lucky enough to be in the right country. Also I’m willing to bet we will get new ways to get coins by then, so it’ll be even faster.