A bit off-topic, but I really want to know.
Are you really using a 15" laptop to edit images on a regular basis? Or do you just start on the laptop and finish on a desktop.
I ask because I wish I had an even bigger pair of monitors than the pair of 24" 1920X1200 Dell's that I use now. It will probably be a while before I upgrade to 4K monitors, and by then I will probably have upgraded to a higher megapixel count than I shoot now.
You must have a problem with your computer, No crashes on Yosemite here. Turn GPU support off.
A couple of Shift-F gives you a full screen, not Apples but the same view. Was the same in Lr5
You can hide individual panes and modules. You can hide the panels. Was the same in lr5
Why do you need a Camera Raw Filter. Lightroom is Camera Raw. Was the same in Lr5
Sorry to hear about your crashing issues. There was one source of crashing fixed in 6.01, so make sure you've updated. Also as Robert mentioned, try turning off GPU in the Performance tab in Lightroom>Preferences. It really works best on machines with large screens attached.
The Radial filter is in the Tool Strip. Press F to get full screen view, or as Robert says, use Shift F to cycle through the full screen modes.
Hold down the Alt/Option key and then drag a side panel to make it as large as you like. Right click on a panel and then untick any of the panels you don't wish to see.
Are you using a hardware calibrator to color manage your screen and previewing in color managed application?
I don't think there'll ever be a full all in one application, but the mix of Lightroom and Photoshop comes close.