Is it possible to change "Add Topic" to "Add Idea" and change "Reply" to "Comment?" I do not know code but found the "Phrases" and "Translate" functions which prompted this inquiry into whether I could effect such changes.
If not easily done by me, could I point my website developer in a direction where they could make those changes?
You can change any UI phrase you want. wpForo provides with a rich phrase managing tools. Go to Dashboard > Forums > Phrases admin page, search for your phrase, edit and change the value.
If some phrase was not found, you can create it. Click the [add new] button, put the identical phrase as a phrase key and your version as the phrase value.