The smell is hard to describe... but did it smell like a metallic burning? This would indicate the clutch burning out. Together with the gear selection fault you have with the car running and then not it sounds like the clutch is on the way out.
There are some more basic tests to see if a clutch has gone:
Stick it into 3rd and try your best to pull away - if you stall then thats good, if you manage to pull away, thats not so good
Drive up hill at speed but at lowish revs in 3rd and boot it to see if the revs fly up but the car doesn't go anywhere - indicates worn clutch due to slipping
The sound that you are hearing with the car off and operating the clutch could be a secondary fault as I have heard it on my 16v. Kinda springy/grating. Could be normal or could be a case of two sick 16vs

they have a hydraulic slave cylinder so it may be worth having a look at it to see if its leaking brake fluid.
From what you've said about it when you couldn't move it and the vanishing biting point, it sound highly unlikely its a gearbox issue.