Also keep in mind that BeerSmith probably is not adjusting for your mash tun. If you're using a cooler, you can either preheat it with boiling water (dump this, then add your water and grains) or bump up the temperature to account for this. Amazingly, that is in another section of the program (Strike/Infusion Temperature) instead of it just being automatic.
I generally cross off whatever temps and quantities BeerSmith gives and put in the ones I calculate from that tool. It has worked pretty well so far.
Also, when you sparge, keep in mind that your grain bed is going to cool down by the time you've collected your first runnings. You want to sparge at 168F but if you use that tool, do not assume your grains are at 158F. Try something like 140-145F and let it go -- or better yet, get your sparge water hot enough (170F), then measure the grain bed temp, go and let BeerSmith calculate it during your brewday and heat the sparge up to the proper temp.
For a narrow kettle, I'd say that .5 gal / hr is reasonable; for wider kettles, 1 gal / hr seems right. It depends on burner strength as well as weather, of course, but you should be in those ball parks. You probably have a 30+ qt pot, so I'd guess nearer to the 1 gal / hr. (Just my experience).