Your Auto:Min pressure should be set where it is "comfortable" for you to breathe, this makes it much easier to fall asleep. The lower the pressure the quieter the machine will be and least annoyance experienced at the mask.
However, that pressure should NOT be so low you feel "starved" for air or feel stuffy. Start low (6.5 or higher) and set any Cflex or Aflex where it feels comfortable to breathe. Then increase the minimum pressure to where it is the most comfortable. If the Xflex setting has changed allow 30 minutes or so of breathing with it before changing it.
Auto:Ramp: Auto ramp is used on those nights that any cpap pressure is annoying, you may go 6 out of 7 nights starting with 8 cm pressure and be just fine, then some nights that may drive you nuts, for those nights you have your machine already set to go with Auto:Ramp. Auto:Ramp pressure can be set a tad lower than your normal Auto:Min pressure. As for the timer I suggest 30 minutes. Keep in mind if your Ramp pressure is 6.5 and your Minimum is 7.0 then the timer will be pretty much ignored as it will be at 7.0 in 5 minutes. But the machine will limit any response until that timer expires unless it is an apnea.
The machine has a built-in settling period (thought to be 20 minutes) during this time the machine may ignore artifact events as SDB events. Everyone has these and they are considered normal, these can sometimes falsely drive up the pressure prematurely on the machine that is why many ignore or limit any onset response.
Auto:Max Pressure: There is really no reason to limit the Max pressure on the machine unless you have other events which drive up pressure prematurely such as snoring. If those pressure increases from snores tend to drive up your pressure to the point where they cause unstable breathing and more SDB or even centrals then you would want to limit any maximum pressure response. But you should observe reports in order to do that effectively.
Once a normal AHI is obtained there is really no reason to increase pressure further.
There is no rule of thumb for pressure ranges, one is not too wide or another too narrow, it is what works best for you. Only concern you should have is using a too low a Minimum pressure, doing so can cause you to starve for air and/or cause features like xflex to become disabled when below 6.5 cm or based on the machine mask or hide certain type of events. In the case of the latter for example if a person starts having central apnea at 9 cm pressure and you start your Minimum at 10 you may completely blow by those events and never know they existed yet when pressure rises above such as from snore more apnea is seen, those apnea may be totally confused by the machine as obstructive when they may have been central.
A little experimentation with settings and observance of reports you can determine which works best for you.
Everyone has a few rough nights when starting out, in fact the average is 4-6 weeks worth.
Vibratory snores: There are a couple ways to look at those, most apnea follow a snore so most machines try to eliminate any snores with increased pressure. Snoring can be a sign of full relaxation and increased risk of apnea showing up as a result. Some snores cannot be eliminated with pressure so in case of those you have to ignore the snores. Remstars will determine this on their own and limit any response to the snores.
Snores can also be a sign of mouth breathing, so if you are using a nasal mask and observing heavy snores consider mouth breathing being a cause. While nasal snores are possible you are less likely to snore with your mouth closed.
someday science will catch up to what I'm saying...