I do not advise anyone to use an WYSIWYG editor. But, if you think that you need such an editor or if you are forced to use such an editor, my advice is to use OpenOffice.
Check the spelling of Romanian texts in OpenOffice with the dictionaries provided by the project rospell.
I did experiment myself with the OpenOffice dictionary for Romanian. My word-list is based on Dexonline, but it also includes the vocabulary from some of my books. This strategy has its advantages and disadvantages: I have a list which includes more philosophical terms, but I also got there foreign words and garbage created by the mining of texts.
I do not intend to maintain my own dictionaries for OpenOffice. Use the rospell project for practical purposes. For experiments, you may download my dictionaries: the ISO-8859-2 version (which can be used on Win98SE) and the UTF-8 version. Pay attention! The UTF-8 version uses the “comma-bellow” form of the Romanian letters şŞţŢ. If you want to use both versions of the letters, study the ro_RO.aff from the Rospell Project.
For installation, these notes are old, but still useful.