1) Easy. If you've travelled from, say, Bristol Temple Meads to, say, Exeter St Davids then you've done the line.
2) Nope, not at all fussed.
3) Don't matter, although with exceptions like the West Highland Line I'd like to see the scenery at least once.
4) Night-time travel, of course I allow it. I'd be royally screwed in the winter time otherwise!
5) Falling asleep on the train still doesn't stop me counting it, I don't understand people's concerns on that. If it's on a train with decent motive power I'd prefer to stay awake of course.
As for having to see both sides of a route in good weather before counting it, that just seems more than a bit OCD. At the end of the day, if you're colouring in a route in your atlas you're usually going to be more concerned about making sure the train goes the way you want than whether you've seen every bit of scenery!
), I have to watch a route as fully as I can both ways, though visibility for me only has to be a few foot. Falling asleep or darkness generally means I don't count it as done. I also aim to do as many loops, crossovers, rare moves, platforms etc as I can. Some might call that OCD, I call it being a pro 
