The customization options for window arrangement are limited in Resolve, compared to some applications. The customization options are flexible enough to have your timeline on a second monitor, though. To do this, under the workspace menu, check both Dual Screen-> On and Dual Screen-> Full Screen Timeline. To switch which monitor the timeline's on, go to Workspace-> Primary Display.
Your program monitor can be on either screen by switching which display is "Primary," also. In the color tab, there are three options for how your program monitor is displayed; Cinema, Enhanced Viewer, or Full Screen Viewer. These options are found under Workspace -> Viewer mode. In the edit tab, there is no Enhanced Viewer, but you can get the same effect by closing other panels and using Single Viewer mode.
Besides having different panels open or closed, breaking out Scopes into a floating window (which you can drag to another monitor if you want to devote a monitor to scopes), resizing sections by dragging the divider between them, having tabbed timelines, multiple bin views, FCPX-like hover-scrubbing with strip or icon view and single view program monitor, or a more Premiere-like Source/Program, there's not much more you can do to customize its layout. You can't "skin" it like winamp. You can't move panel positions relative to each other. In short, everything you need to do your job is in there, with nothing superfluous.
Whether or not BMD plans to add these features is anyone's guess, but their development team is extremely responsive to user feedback on their forums. They've implemented changes that I've recommended on multiple occasions (the thin red line designating panel focus with the 15.2 update was something I suggested.)
Command +/- is one way to zoom, alt/option mousewheel or two-finger drag is another, dragging on the +/- zoom slider is another. If you want to adjust track height, so that you can see more stacked layers, click on the "timeline view options" icon in the center of the screen, next to the zoom slider.
There are multiple ways to scale in DaVinci, and a couple of points in the signal chain where the scaling might occur. You've found edit scaling, but there's also project-wide scaling under Project Settings-> Image Scaling ->Mismatched resolution files.
Then under the color tab, there's input sizing, output sizing, node sizing, and reference sizing. The order of operations for color page sizing is covered in chapter 119 of the user manual.
Probably not, depending on what kind of effect you're after. Fusion is to DaVinci what After Effects is to Premiere, except it's built in, and it's node-based, so conceptually it's more like Nuke than AE. But if you just need simple things like blurs, keys, object removal, lens flares, etc, you can find those things in the OpenFX tab of the color page, or the Effects Library tab of the Edit page. You can also install any plugin that supports OpenFX. Genarts Sapphire, BorisFX Mocha, and filmconvert are all popular. Premiere supports effects presets and templates better at the moment than DaVinci, but Fusion integration is new, and this should change soon.
