I think we're out of new controls long time ago..
Missing from my point of view are those that can be focused like in custom drawn (that it stopped their development too). Transparency is not an issue when you really need to focus things in the form to speed up the usability of the application (specially those that has repetitive input in edit fields from user).
I've not tried FPGUI because I'm used to the LCL and the classic form editor.
I never see the fully customizable form, never finished a complete drawer (also because custom drawn not works fully on desktops), not to be despective is a really good job done by felipe, I wish to help, but I'm not as good making components as others here
Using Lazarus owner draw components (i.e listbox owner draw item) just broken some of my apps because the drawing takes time and is not fully tested in real case scenarios. Too lazy to report bugs now that I know the time they take to will be fixed (sometimes never) So I opted out in using broken things.
But I like all the options here, but I don't see the customization an easy thing for lazarus developers.
That's all!