I use the selector in my 07 all the time. When turning a corner, I sometimes keep it in first gear because during the turn I coast, and normally it'll shift into 2nd. But then out of the turn I want to accelerate and first provides the desired power.
Bliping the gas is the best way to shift, no need to put so much stress on the clutches if downshifting. But also no reason to downshift, if you stomp the gas, and it has the ability to use a lower gear it typically will use it. I say typically because my 07 refuses to downshift from 3 to 2 above 40mph (note redline in 2 is at 60mph). Even if I select 2 it still won't shift, I have no idea why. Very annoying. The brakes are more than enough to stop the car downhill, just pulse them, holding constant brake pressure can overheat them much faster. Only real reason to downshift on a hill is if your pads just wore out and you are on way to shop and want to save the rotors. Also keep in mind that you have to go though second gear to get to one, even if you stopped at a light sitting in one, you have to select 2 on your way to one and it will initiate the shift (likely not complete it though).
Long story short is no slushbox can be run for any degree of performance, they're for lazy people. I inherited my auto CR-V and so I'm just going to keep driving it till it dies, after that I will never own anything but a manual transmission. More fun, more mpg, lasts much much longer.