Wow... a lot to unpack in your post, but I'll try....
I noticed that Tiki-Wiki is around 21 times larger than e.g. Dokuwiki.
290MB vs. ~ 13.5MB.
Tiki has an "all-in-one" model. See https://tiki.org/Model for details.
Have you reviewed the doc site? Most options are fully documented.
A profile with everything on? No. But the Configuration wizard walks you through all options, allowing you to turn on what you want.
Menus are difficult to set up.
I want a horizontal menu as "upper bar" (under the logo).
But I just want a narrow bar with the words (Home | Forum | Blogs | Wiki etc ..) in it. No frame, no title etc.
See http://doc.tiki.org/menu to create your own menu.
You can use the Module logo to set all options, including titles and subtitles.
I think it depends on how wide you set your site to be.
Feel free to check out my Tiki for Smarites site