Here's a quick rundown of what I tracked down or just plain guessed at for most of the stuff you asked about. I'd be shocked if I was anywhere close to 100% correct but here we go anyway!
AAD.BrokerPlugin | Azure Active Directory AppX Broker Plugin, eg Microsoft's cloud service mostly used in business environments
AccountsControl | Seems to be involved in linking accounts, email addresses and phone sync
AddSuggestedFoldersToLibraryDialog | Fairly self explanatory
AppResolverUX | Seems to be a user interface asking how you want to opening things, similar to OpenWith.exe perhaps but an AppX build.
AssignedAccessLockApp | Most likely an AppX companion for Remoting and Privacy > Assigned Access
AsyncTextService | I would guess this is used in 'texting'. Seems to use location, maps & people
BioEnrollment | Hello setup UI eg facial recognition and other bio-metric logins
CapturePicker | Seems to be involved in helping users choose what to share, eg specific program windows or an entire screen.
CBSPreview | Camera Barcode Scanner (PoS)
CloudExperienceHost | Used in a variety of contexts, seems to be a generic AppX used for 'WebApps' These can be anything from being account related (eg LiveID, MS accounts, enterprise logins) to phones, windows hello, device management, targeted content
ContentDeliveryManager | Windows Spotlite, eg Tailored Experiences using Diagnostic Data, your account, a linked phone, Windows tips, suggestions
Cortana | Cortana, the annoying talking 'helper' currently integrated with search
CredDialogHost | A generic AppX UI that could be used in a variety of contexts, from the XBoxApp to Phones but currently only seems to be involved in Enterprise Authentication?
ECApp | "Eye Control" UI via camera, also seems to handle speech
EdgeDevToolsClient | An extension to edge containing tools for web developers eg a debugger, emulator and more
Edge | The AppX browser shipped with Windows 10
File Explorer | A (currently) less useful Appx version of explorer
FilePicker | Seems to be a generic AppX version of the 'open/save as' dialogs that could be used in a variety of contexts, eg as part of other apps?
HolographicFirstRun | "Get Started" for Mixed Reality
immersivecontrolpanel | The AppX Control Panel eg "Settings"
InputApp | AppX interface for Text input eg handwriting, touchscreens
LockApp | Seems to be an AppX interface for Lock Screen 'extras' like cortana, feedback, now playing, suggestions, etc
OOBENetworkCaptivePortal | part of Windows Setup 'helper' UI to guide the user through setting up network connections, eg helps noobs enter wifi passwords etc
OOBENetworkConnectionFlow | part of Windows Setup 'helper' UI to guide the user through setting up network connections, eg helps noobs enter wifi passwords etc
ParentalControls | Fairly self explanatory, AppX used in "Family" settings eg child/parent accounts and/or timed control
PeopleExperienceHost | Fairly self explanatory, AppX Contacts/People bar
PinningConfirmationDialog | AppX used after installing an app, eg Do you want to pin (AppName) to the taskbar?
PPIProjection | Perceptive Pixel Interface Projection, would seem to require specific multi-touch hardware still in development?
PrintDialog | A generic AppX UI usable by a variety of applications. eg if you might need to print from any Windows Store App, keep it!
SecureAssessmentBrowser | Seems to be a generic AppX 'Browser' usable for test taking. eg online courses
ShellExperienceHost | AppX components of Explorer, eg start menu and taskbar context menu among others
SmartScreen | AppX component that uses the cloud to check apps, sites etc. Also required for the DesktopAppInstaller to function properly.
Win32WebviewHost | A generic AppX interface for regular apps that want to make use of it to throw stuff from the web onto various sections of the desktop including notifications, mixer and likely more. I'd think of it a bit as ContentDeliveryManager for regular applications
Windows Defender | Fairly self explanatory, part of the built in Anti-Malware
XboxGameCallableUI | Seems to be a generic AppX UI usable by a variety of xbox related games. eg part of the core xbox UI
xgpuejectdialog | Appx used for safely 'ejecting' external video card devices. akin to safely remove for usb drives but for external gpus
Advertising.Xaml | Generic AppX usable by a variety of apps to aid in selected advertising. Unfortunately some apps & games rely on this as a dependancy
DesktopAppInstaller | An AppX UI used to aid the user in installing other .AppX or .AppXBundle files without requiring the use of powershell commands
vp9videoextenstions | Generic AppX comonent to allow the use of an open source video codec, VP9, developed as part of the WebM Project by Google. May be required as a dependency by certain apps down the line.
Xbox.TCUI | Seems to be part of the Xbox UI though I am unsure why it is separate from XboxGameCallableUI