There's a free Thesaurus add-on you can get to from the toolbar at the top of GoogleDocs. Doesn't seem to work very well, honestly, but you can also use the native "define" function, as that will also generate a list of synonyms in the sidebar, which can be easily cut and paste into the document.
On handwriting: I feel that a reasonable goal for handwriting is being able to fill out a form, and write a one-line note. Any writing beyond that, we all typically use AT, so why sink unnecessary energy into more work on it.
