None of those except #1 and #2 are core WP, the rest basically rely on what theme you choose, and various plugins.
WP itself is pretty garbage, non-intuitive for end users, and not easy at all to start from scratch should you want to build your own theme and not rely on a huge plugin stack. There is a lot of magic going on, like meta-data being stored in the CSS file, what?!? And a huge theme waterfall hierarchy, and a billion PHP functions for the API. There is no real theme framework or template system built-in, an incredibly basic and poor custom field manager. They expect you to build themes by using dozens of PHP hook functions and echoing out bits of HTML here and there, making it very difficult to ever track down exactly where a piece of output is coming from. Was it a menu, a widget, a custom field, the page content, a header/footer file, an override template, the functions file, a plugin, WHERE!!
I could go on and on for days about the many frustrations of WP. But that doesn't matter, because most people only use WP so they can install a huge stack of plugins to actually make it work and do something useful, if you're ok with the huge amount of code bloat you get with it.
And don't even try to write any custom CSS, because you'll find it nearly impossible to override all the other CSS spit out by the theme and plugin stack, unless you get very hacky to try and force your custom CSS file to be output last after every other style.
Hey, I work mostly on WP, lol, because everybody uses it, but it's far from praise-worthy, especially for a developer who wants complete control over the site. Or who wants a proper template system. Or who wants to highly optimize their output, or use a proper toolchain for development, staging, and production, etc.
Use it if you want, but it requires constant maintenance and updates, testing, and review to make sure nothing breaks when your plugins update every 4 days.