Yes! - It's quite active!

Yes - But it's still in alpha phase because Blender LTS 3.3x has yet to be released.
However, you can download Armory experimental builds that are compatible with latest Blender daily builds, that are built on Blender 3.x, non-LTS source.

Please follow basic troubleshooting steps from here.
If error(s) still persist, please open an issue report or ask the community for help at any of the Armory-related community platforms.

The official Armory manual has a full list of logic node references.
The references contain detailed descriptions of what each logic node is capable of and what features it comprises of.

To avoid bias, you'll need to conclude that on your own.
Here is a list of pros and cons of both game-engines that is maintained by the community.
Feel free to open a pull request if you feel additional information could be added to the list.

See here on ways you can contribute to Armory. Thank you for being interested!