Questions on custom tile improvements

[Manhunter07]

Hello,
I'm new to this forums, although I've been reading here for quite some while now.
I am stuck at creating a mod that adds tile improvements, but I am having a few problems there.
It would be a pleasure if you guys could help me out.
If one (or more) of you have an answer on any of my questions, I already want to say thank you and would love to hear it. I did a loooot of research, but couldn't find anything valuable over the last days.

1. Whenever my improvement has been built, the button does not disappear. In fact, I can just re-build it over again. Also, when it's under construction, and I press the button, it starts to build the improvement from scratch, not like it is with the standard improvements from the game. Any idea of how I can define if an improvement is available for building only if the tile does not already have the same (or comparable) improvement built on it?
2. Is there a way I can define the movement costs for land/sea units that move onto and from my improved tile? I know how it does for landscapes, but I could not find a way to get it working with improvements. Any idea on this?
3. Is there a way I can animate the texture of my improvement, like foating water etc?
4. I have tried to disable roads on my improvement, using XML/SQL with RemoveRoute, but could not get it to work. Also, does it prohibit the user from building roads there in the future or not?

Thank you a lot if you could give me an answer to this!

 

[Manhunter07]

Wow seriously, does noone have an idea on tile improvement modding here? Or is this forum simply inactive these days?