welcome to srp

1. depends most on your shaving and stropping skill, then your beard preparation, then your beard you have and finally the actual razor. between 1 shave (if you damage the edge) and years, probably few weeks at the beginning
2. depends on where the razors start. if they've been expertly honed and need just a slight refresh that's quite easy, if they have just come from ebay probably will take you at least several weeks.
3. depends on the razor, a touch-up should take about a minute, razor from ebay few hours after you know what you're doing
4. depends on the condition of the razor you want to hone.... same idea as above, probably $10-$15 is the minimum for a hone that would be good for touch-ups but you'll have to spend good time looking for one and then another few hours to lap it.