1. I use a cane, but I think that the human is the one in control, and so they tell the dog when to change direction, but if it's aroute they do without alteration every day, the human might only need to give the dog a command if they are deviating from the standard route.

2. Yes, kind of. I can judge relative distance more accurately than actual distance.

3. I don't think I'd try surgery until the success rate was higher, but the realities of my visual impairment mean that during my lifetime I will never gain much vision.

4. Definitely.

1. I'm a cane user, so can't answer to this.
2. I'm very bad at calculating distances based on hearing, because there are many conditions that can affect the volume of the sound that reaches my ears. For example there's a ~100m or ~300ft long narrow street close to where I live that always fools me, as I can be at one end and hear cars at the other end that appear to be very close since there are buildings on both sides reflecting and preventing sound from propagating in all directions.
3. You mention risk, but don't mention what kind. If it was the risk of dying I'd go for it even if I only had 1% chance of living, because for me life is worthless without quality. If, however, you meant a 50% chance of having a stroke that could potentially worsen my quality of life even further I wouldn't risk it.
4. Not generally, but for using computers I do rely entirely on my hearing and do things that I never thought were possible for a blind person to do before losing my sight.

I think 1, 2, and 4 you could find answers online by reading articles and doing your own research.