In a 6 gallon, you don't have a lot of options. I might suggest a planted cherry shrimp tank, could be fun. You can fit a whole bunch in there, up to 40 - 60.
Don't chase chickens. Remember, to him a human is a terrifying giant whose motives he doesn't know. Imagine an elephant running at you, you'd probably want to get out of there as fast as possible. I'm not entirely sure what you're asking, but I'd say stop chasing him, and if you want him to be...
Hard to say, both are great breeds. I'd probably keep the d'Uccle because I'm not a huge fan of how frizzle looks, but it's really up to you. Keep in mind that if you do keep the cochin roo, it wouldn't be advisable to hatch chicks from the cochin hens. The chicks would have a 25% chance of...
I tried to give mine some climbing branches, ended up scaring them. Apparently they don't like change, they spent a few hours huddled in the henhouse. I took the branches out.