As was said earlier, there's no real hard & fast divide between a "professional" and "amateur" camera--the real difference is behind the camera. An FE was and is capable of doing the job in well over 90% of the situations a pro might find himself/herself in. And, in fact, if discretion is part of getting the job done, the FE is a better choice than some "pro" cameras--I often find myself wishing Nikon could cram the guts of a digital camera into an FE body, with its superior size (smaller = better to me), rugged construction and comparatively excellent viewfinder (particularly when pimped with a K3 screen).
In the days of film, the camera body was about the least important aspect of the gear equation--the lenses you put on the front of it and the film you put in it were much more important. As you could mount the best Nikkors on the FE and load the finest film in it, it could produce results the equal of any camera in the Nikon line.
I love the FE so much that when my first one--a bit tatty with age, but ever dependable--was stolen last year, I searched around and got another to replace it as soon as possible. I don't use it as much as I once did, but it is so fun to shoot with that I regularly find excuses to pull it out and let it play on occasion, just to renew our joyful friendship. It's a great little camera!
Oh, and to correct a slight misstatement offered earlier--the MD-11 motor drive will drain the batteries if you forget and leave it turned on, but this was rectified in the MD-12--it will turn the meter off after a period of inactivity, saving battery power. I've got an MD-12, and it's really an excellent--and, nowadays, pretty cheap--addition to the camera's functionality in certain situations, when the increase in size/weight may not be a problem.
The difference between an amateur and a pro is an amateur dreams about increasing his inventory of equipment, a pro his bank balance.
Shall I tell you my story about my FE that I've told five million times here over the years? Yes? Right then.
So I was outside shooting at night in the dead of winter. It had been warm enough to melt snow earlier on in the day, but it got cold enough later that the puddles turned to ice. I had the camera on a tripod for long exposure. I went to go grab something out of the way, then walked back. On the way, I slipped on the ice and grabbed the tripod. Camera fell onto the pavement hard, as did I. Camera was fine, but the pavement had a small gouge in it.
I would trust *any* of those bodies to just keep going. They don't make them like that anymore. They should start. I'd be more apt to spend more on a camera that is built like the FE than the current plastic crap offered nowadays.