Questions about Chinese

I started playing aoe3 recently after not having played it for a really long time and I have some questions about China. So I pretty much only play treaty game mode and generally nr55 or nr60, so this is the situation these questions are based around.

1. What is an eco score that I should be attaining at the 60 minute mark? I currently hit around 3.3k-3.5k, depending a little on the map and amount of trees, but idk if this is good at all.

2. I usually spam ckn and quiang, but I usually end up running low on wood. In this situation should I try to squeeze out as many as I can or switch over arq and chao? It seems like they accomplish the same job, just a bit worse, but im not sure.

3. On a map like Ori, is there anything I can do in the situation where im running out of wood? I keep my factory and porc tower on wood, but that isnt a reliable enough outcome to build ckn, qiuang, walls, etc

4. I use the 30 rattan shields home city shipment which can be used infinite times, but a lot of times it doesnt let me send it. How exactly does this work?

Sorry if this post is a bit long. Ive read a lot and watched videos about how to play china but I cant find answers to these things, so any help would be very much appreciated!

Also sorry if it is formatted badly, I typed it on my phone.