Yup, what George said. And intake valves have cool incoming air to cool them slightly, while exhaust valves deal with hot air flowing past them, which is why exhaust valves have to have a larger cold gap than intake valves. As for comparing gaps with other engines, there are lots of variables such as valve seat design and material; valve material; head design; speeds the engine turns; timing, fuel, etc. that all affect what the hot gap will end up being.
When I checked my valves, if they were all .001 too loose, I probably would have ignored them until the next check...except for a tiny increase in engine noise, .001 loose wouldn't have had a negative effect. But too tight can have a negative effect under the right conditions. Its highly doubtful .001 tight would hurt anything...my bike has been running great until I parked it last fall. But .001 tight now could equal .002 tight by the next check. Since I was someone who had little maintenance time in the summer, and preferred riding to wrenching, it would most likely be another 25k miles before I checked my valves again, so I wanted to make sure they were right on the money now.