I have had one for a couple of years, no problems at all.
Regarding your points:
1. I am 140-ish pounds and it's fine for me. No issues with the expander.
2. No, that's fine too.
3. I like a quick-handling bike so a short a-c suits me fine. IIRC different lengths are available.
4. No idea, mine are disc-only.
For pictures of it in use see here http://www.andrewhowett.blogspot.co.uk/ ... -bike.html
tzenno makes a valid point. The crown is quite wide and will protrude slightly on bikes with conventional headsets. Looks a little odd but works fine. Pictures of it on my old bike here (click pic to make it bigger) http://andrewhowett.blogspot.co.uk/2012 ... ruins.html
New bike has an integrated headset and it looks much nicer.
Overall I would definately recomend it. Light, much nicer to ride than my previous, steel, rigid fork and so far reliable.