1. don't know
2. depends on you and what you're trying to do/say with your accomplishment, many routes claim variations,
3. in my view no, unless one direction has a clear advantage over the other, then it would be two separate records.
4. the Spot is merely the most recent and currently preferred verification technique.
if the trail has enough activity to allow frequent human contact, that would serve as adequate verification. pass out a small card with your email address that asks them to email you, stating the details of your encounter. have them email any photo they may take of you. of course this could slow you down a tad if you are the talkative type.