My top two pet peeves are the lack of a separate option browse (editing) / browse (consulting) and the frigging unformattable scroll bar.
Just recently I hit a wall with the latter. Didn’t realize that building a branded theme on the default blue summit would bite me. Try finding a default theme that has a scroll bar that is harmonious with the colour eggplant. Especially if the background is very light grey and the portal rows solid eggplant (master detail)
Using Theme Editor I can see that there are 18 references to CSS classes affecting the scrollbar in the Minimalist Touch theme. As shown below, the number at the front is the line number in the CSS.