can it be possible that dinosaurs came from bird like animals in the trees?
the dinosaurs might have evolved from ancestors of the first birds... some came to the ground and adapted to ground living, but retained the feathers to help insulate body temperatures. while the ones in the trees continued to evolve into birds, the rest on the floor evolved into dinosaurs... which help explain that some of the more birdlike dinos have feathers that have no flight capability or purpose whatsoever. although the feathers on some raptor's forearms would help it turn or stop with more agility and balance.... imagine when making a sharp turn evading predators or chasing prey... while doing so, you stretch out the arms to get balance and also with feathers, you are able to use it like a sail to make the air current help you change your direction more rapidly. the raptors might use these feathers to aid it to make a farther and higher leap onto a large prey's back.. from the ground or from a higher vantage point.

what do you guys think? is it easier to evolve from feathered to no feather or from no feather to feathered?

No!!!!!!!!!!!
Dinosaurs evolved from archosaurs, and birds evolved from dinosaurs. Plus, the first bird appeared around the late Jurrasic, almost halfway through the Era of the Dinosaurs....

REPTILES > Diapsids > Archosaurs > Dinosaurs > Birds
Diapsids are archosaurs, crocodillians, and modern day reptiles
Archosaurs are dinosaurs, pterosaurs, crocs, and birds,
Synapsids are the reptiles that evolved into mammals.



Or just likely more for display...I doubt 'down' would provide you with enough to use as steering...

I think feathers evolved first for insulation, then for display, then for flight.

That probably was the case, and it would not be unreasonable. After all, it is believed that pterosaurs probably had a kind of scale-like "fur" for insulation on their main torsos (not to be confused with mammalian hair).