I’ve got two problems with TinyMCE installed in a module. You can see them both if you use the guest login and play around with the KoopsMailinglistX module.
First, I get the extra <p> </p> for every line break. This has been brought up elsewhere, but I haven’t seen a solution.
Second, both in the editing field itself and in any popups such as insert/edit link produces this js error on saving:
setVariableModified is not defined
The save works anyway, it just generates this error.