it sounds like you actually MOVED database in step 3 and simply SWITCHED database in steps 7 and 9.
When you MOVE database you cut/paste database from one drive to another, when you SWITCH database you simply select the database you want to be active.
In step 9 you switched to the internal empty database and your collection disappeared. Then you created a brand new collection and obviously there were no hotcues, no playlist.
That said, insert the thumb drive in the new computer, open preferences > advanced > database, you should still be able to SWITCH to the external database from the drop down menu in the white rectangle next to 'select a drive'. If so, you will see again your original collection with playlist and hot cues.
At this point I strongly suggest you a library backup before you proceed (let us know if you don't know how).
Then you can click on the black >> button in database management and the 'move database' button will appear. Click on that button to MOVE DATABASE from the external to the internal drive and you're done..
No.. you still have to relocate tracks.. mass relocate..
Ok. One thing a a time, let us know where are you now