Will I ever be able to highlight text

And to make it more usable why not assign a keyboard shortcut to the highlight color as a character style.

You may have to choose fn+F1 depending on how you have your function keys assigned in the Keyboard preferences panel.

1. Select some text, and apply the Text Background color of your choice to this text.
2. With the text still selected, click on the Character Style selector, and click the now visible '+' symbol to add a new style.
3. Give it a meaningful name.
4. Move the cursor to the right end of that new style name and a > appears where you can assign F1 thru F8 keys as shortcuts.
5. Type some new non-highlighted text, select it, and press your function key assignment to apply the highlight.

You can even make gradient text into a character style using the new features in Pages 8.1.

It has for a long time, but it is hidden on the Advanced Options panel (gear icon on same button row as text attributes). The proper text highlight is known as Text Background in Pages 8 and 8.1.

Unfortunately, there are no shortcut keys, or toolbar item to invoke this feature. Color well for static colors, and globe for a truly screaming yellow highlight.

I am saying the feature is there and quite usable — just inconvenient.