Thanks for sharing this screenshot. ACtually, we are instructed to ask users to create separate topics for a new issue and post one issue on a topic
But I will reply all your issues:
Point 1. Remove dropdown and star ratings: Add this custom css in wp-admin > appearance > customize > custom css
div#wplms_instructor_course_appointments .instructor_ratings,div#wplms_instructor_course_appointments .instructor_selectable_dropdowns{display:none !important;}
refer:
http://prntscr.com/umm4x0
Point 2: I can't translate: Yes, this is an issue with react Big calendar which we are using in wplms appointments.
The translation of this thing is an issue so I can provide jquery code to translate if you want. I have only this option
Point 3: Right now, we have only these formats supported which is provided in this dropdown list