things/linedefs etc.

[tyrzi]

I think thing's type numbers are replaced and linedef's action numbers too so is there any place to read them or is they coming in SRB2wiki some day?

 

[Scarbo the Black Sheep]

They have been replaced. Look in the linedef types list in SRB2DB, as well as the Thing type lists. They'll show you the names.

As far as how to use them? Some can be done with the Wiki currently; new linedef types, you'll just have to figure out yourself. Study what the official map does to implement the gimmick and decode how to manipulate the parameters.