On your picture, what happened between 4 and 5? Any transit between them or they just leaped (or missing or not found)?
Quite a few fossils, like Protarchaeopteryx.
Protarchaeopteryx had long legs, and could have been a quick runner. It had well-developed, vaned feathers extended from a relatively short tail; the hands were long and slender, and had three fingers with sharp, curved claws. Its bones were hollow and bird-like, and it possessed a wishbone.[5] At around 1 metre (3.3 ft) in length, it would have been larger than
Archaeopteryx.[5]
Protarchaeopteryx also had symmetrical feathers on its tail. Since modern birds that have symmetrical feathers are flightless, and the skeletal structure of
Protarchaeopteryx would not support flapping flight, it is assumed that it was flightless as well.[6] It has been suggested that it could have had an arboreal lifestyle, jumping from tree limbs and using its forelimbs for a form of parachuting.[7]
https://en.wikipedia.org/wiki/Protarchaeopteryx
Barbarian, regarding what feathers are for:
Just like today, they also provide insulation and are used for display. Flight came much later. Features that are useful for one thing are often adapted later to other uses. Would you like to learn more about that?
Already have. It's just a fact. Feathers are used in all birds for insulation, and in almost all birds for display as well. Flight came later.
Do you agree that it is likely that feathers come in and the wings gradually evolves to have more and more feathers and eventually to the point they can fly?
Not that simple. You're missing a lot. You see, the motion for flight is also preadapted, as is the respiratory requirement. Would you like to learn how they were adapted long before there were birds?
Before that as the wings getting better they provides nothing except dead weight (and air drag),
No, that's wrong, too. Do you think ostriches have useless wings?
that will put the early non-flight in-between-birds in a big disadvantage.
Nope. For the same reason wings are adaptive for ostriches.
I know about the smaller extinctions, but remember those are not "true extinction" events.
A true extinction event is when at least one species goes extinct. The Quaternary and Pleistocene extinctions had many more. A majority of large mammals, for example, went extinct in those, as the environment changed.
A lot of the animals survived
At least 10% of living species show that they've been in existence more than 200,000 years, according to the research you mentioned. That's a lot. And as you learned, it effectively rules out YE creationism.
It has been mentioned multiple times.
Yep. An impassible problem for YE creationism.
"Not according to your guys. About 10% of the species noted are over 200,000 years old."... I don't remember saying such a thing?
The study you cited did. Only about 90% of living species are younger than that. If YE creationism were true, 100% of them would be.