I did a quick test and the Keywords that are returned don't have <b></b> tags.
They are returned in this format:
Test mode | Authorize | Test | 06-18 | eCart
But the Abstract is returned with <b></b> which is how it is returned from the API Call.
In regard to the results set, I'm not sure you can do any thing if part of the word is entered because the results are returned from the API call.
But you might be able to do some checking on the search term and try adding words that always return results.