I realized I can install a second portable version and get the default hotkeys from there. No need for Steven to chime in.
Here is the list all all hotkeys that are enabled by default as of MB v3.4.8033. Thanks to psychoadept for pointing me to the Wiki.
Edit: Amend Clicked Column F2
Edit: Configure MusicBee Preferences Ctrl+O
Edit: Copy Tags and Artwork Only Ctrl+C
Edit: Custom Search Ctrl+F
Edit: Edit Tags Shift+Enter
Edit: Paste Copied Tags Ctrl+V
Edit: Select All Ctrl+A
File: Remove (Delete) Delete*
File: Remove (Hard Delete) Shift+Delete*
File: Rescan/Add Files Insert
General: Refresh F5
Multimedia: Next MediaNextTrack (global)
Multimedia: Play/Pause MediaPlayPause (global)
Multimedia: Previous MediaPreviousTrack (global)
Multimedia: Stop MediaStop (global)
Now Playing: Start/End Bookmark Ctrl+D
Playback: Play Next Track Ctrl+N
Playback: Play Now Alt+Enter
Playback: Play/Pause Ctrl+P
Playback: Previous Track Ctrl+B
Playback: Queue Last Ctrl+Enter
Playback: Queue Next Ctrl+Shift+Enter
Playback: Stop Ctrl+S
Player: Volume Down Ctrl+Alt+Down
Player: Volume Mute On/Off Ctrl+Alt+V
Player: Volume Up Ctrl+Alt+Up
Rating Now Playing: 0.5 stars Down Ctrl+Alt+NumMinus
Rating Now Playing: 0.5 stars Up Ctrl+Alt+NumPlus
Rating Now Playing: 0 stars Ctrl+Alt+0
Rating Now Playing: 1 stars Ctrl+Alt+1
Rating Now Playing: 2 stars Ctrl+Alt+2
Rating Now Playing: 3 stars Ctrl+Alt+3
Rating Now Playing: 4 stars Ctrl+Alt+4
Rating Now Playing: 5 stars Ctrl+Alt+5
Rating Now Playing: Unrated Ctrl+Alt+-
Rating Selected Tracks: 0.5 stars Down Alt+NumMinus
Rating Selected Tracks: 0.5 stars Up Alt+NumPlus
Rating Selected Tracks: 0 stars Alt+0
Rating Selected Tracks: 1 stars Alt+1
Rating Selected Tracks: 2 stars Alt+2
Rating Selected Tracks: 3 stars Alt+3
Rating Selected Tracks: 4 stars Alt+4
Rating Selected Tracks: 5 stars Alt+5
Rating Selected Tracks: Unrated Alt+-
Tabs: Close Tab Ctrl+W
Tabs: Create New Tab Ctrl+T
Tools: Analyze Volume Ctrl+Shift+V
Tools: Auto-Organize Files Ctrl+R
Tools: Auto-Tag by Album Ctrl+Shift+T
Tools: Auto-Tag by Track - Update Tags Ctrl+L
Tools: Rip CD Alt+R
View: Show Now Playing Assistant Alt+J (global)
View: Show Now Playing Track Finder Alt+F
View: Show Tag Manager Alt+E
View: Show Visualizer Full Screen F11
*- Delete and Shift+Delete are assigned as hotkeys but they cannot be reassigned. Delete acts like the Delete menu command (Remove, in playlists). Shift+Delete will remove selected tracks from playlists and the library and send the files to the Recycle Bin. Whether you get a warning for this will depend on your Confirmation Settings.