The reason the answers to your questions are so variable across the net is because A) the desired appearance is wildly different from one to another and B) a lot of it doesn't matter or the variables are so widely dispersed no answer will be perfect for your case. 3 to 1 or 6 to 1 dilution, how long to etch? Less important than the temperature of the solution, for example.
The other questions really depend on what materials your laminate is made from and what desired outcome you have. What do you want it to look like?