Gonna have to disagree with you. Having used numerous website "builders", Bootstrap Studio is literally the best at what it does. It's an astounding program for the money, and I have had only one or two things that I was unable to do with it (and one of them was immediately addressed by the developers, who are equally amazing.) This is probably one of the most powerful, stable, and easiest to use pieces of software I've ever encountered.
But sure, there is a learning curve. And to get the most out of it, you need to (at minimum) have a basic familiarity with the Bootstrap framework, CSS, and to a lesser extent, HTML. The best thing you can do is follow along with the video tutorials to get a basic understanding of how the user interface works.
As for the dropdowns not being "customizable", this may be true in terms of how one can customize a dropdown created from scratch with pure CSS, but that's because Bootstrap's dropdowns are made to look and work a certain way, and not really meant to be modified. Nevertheless, there are ways to change most aspects (size, colors, fonts, even adding submenus.) And you can always create a custom menu using a menu builder and add it as a custom code block.
The Bootstrap Carousel has similar limitations, but even it is still quite customizable if you learn your way around the classes and rules. For example if you look at this website which was built entirely with Bootstrap Studio, you will see there are TWO Bootstrap carousels on the home page. The first one is in the header (you have to wait about 5 seconds for the images to start changing, just be patient), and the second one is all the way at the bottom, where the carousel has been totally modified to display client testimonials as opposed to images.
http://heartandsoulcenter.com/
So to say it's not "customizable" is completely inaccurate. In fact, I've even uploaded that bottom carousel to the online user library, so other BSS users can use it.