Hey digitalfaber,
Thanks for the feedback and the bug report. I’ve tracked down the bug you mentioned. The fix will go out with the next version, but if I don’t get to that in the next week it may not be until July (got a busy June). If the fix is urgent and you’re comfortable with PHP, here’s the commit with the fix.
Yes, I should have got the translation file out with the initial release. But I confess it’s an area I’m not very familiar with. You can find a .pot file I generated in this issue thread on the GitHub repo. I expect to get this into the next version, too.
I am torn about adding a page in the settings panel to customize the labels. I’d like to keep the setup and options as simple as possible. It does offer a way to use your own booking form HTML output, though. You’d need to hook into the rtb_booking_form_html_pre filter. Check out the rtb_print_booking_form() function in /wp-content/plugins/restaurant-reservations/includes/template-functions.php if you’re up to it.