Answers to questions:
- You need to have some knowledge of how things work. Most of the code (nearly all) will be created by Wappler.
- Not available as yet. See Adobe XD extension for Wappler. Maybe a surprise introduction in Wappler v5 which is due in a couple of weeks.
- The front end uses Bootstrap which is extremely customizable. See https://getbootstrap.com/.
As far as the features are concerned, all that you have mentioned as your end goal is possible with Wappler.
Have a look at this playlist:
https://www.youtube.com/playlist?list=PLUjqTJN3byC9fUoXFnoNGlYBCBZOJUPca