I think the plants will probably be OK, but I'm not sure about the newts.
I don't have any personal experience with this species, however this may help:
Also, I think on your old thread, there were pictures of fish in the palandarium already? It's generally not a good idea to mix fish and newts. Newts will eat whatever they can fit into their mouths. If that happens to be your fish or a snail, then it can end badly. Some examples: http://www.caudata.org/cc/articles/M...isasters.shtml
This article says that crested newts are poisonous (though compared to other species they are one of the least toxic newts): http://www.caudata.org/cc/articles/toxin2.shtml