Sure! Start high and go down at your own pace in both carrier freq and brain freq.
Absolutely.
(My personal tendency is to throw discretion to the four winds and go for the goods in all things.)
Move the carrier frequency down in 5hz increments and move the brain freq down in a similar manner--as you adjust.
Further, I know when you're just starting out, it's a good idea to just go 30 minutes. Then, once you can handle that, go for the full hour.
Or... you can just jump right in!!! 
