This general centering issue was filed here: https://bugs.chromium.org/p/chromium/issues/detail?id=598805
For dragging 1px width change: https://bugs.chromium.org/p/chromium/issues/detail?id=598818 See the section below, "Resizing, one pixel at a time".
For the missing resize bars: https://bugs.chromium.org/p/chromium/issues/detail?id=598822 See the section below, "Resize bar is not always available".
For the missing rotate button: https://bugs.chromium.org/p/chromium/issues/detail?id=598829 See the section below, "Rotate not always available"
For the missing "hover" behavior: https://bugs.chromium.org/p/chromium/issues/detail?id=600180 See the added comment below.
Turns out that you can toggle the hover/touchscreen behavior, under the "overflow menu" > user agent type > (desktop|touch|mobile).
When you select anything except the default (mobile), then there is visual feedback telling you the mode you are in. This visual feedback guides you where to look for changing that mode. For example, "desktop" is shown in the upper right:
And even if you change the pixel density, this info is reflected in the same area, near the overflow menu.:
And selecting "touch", shows similar mode feedback:
But mobile, being default, does not provide any indication that's I'm in any particular mode, or where/how I might change it: