NO-IDea
Smash Lord
Snake's camping tends to draw me to him, especially the grenades. I could have probably done a better job of out-camping, though.
Gimping him was difficult too; whenever I got him off the edge he would jump then up-B to get the maximum vertical speed very quickly. Spiking him seemed almost out of the question.
again, sh-homing missles alone should do the trick for out-camping. SH super missle for the occasional change in tempo. As for gimping him, if he immediately uses his second jump (usually followed by a n-air or air-dodge,) abuse your z-air to hit him while he's mid second jump. Then he's forced to use his cypher while giving you time to reach vertical height XD. This is of course assuming that he's off ledge when he uses his second jump and he's close enough for the spike (meaning gimps usually happen when he's below 50%.)
Eventually, he'll read this and instead attempt to go low and aim straight for the ledge. There's really nothing you can do but ledge-guard at that point. He'll get invicibility frames before you pull off the spike.
You won't get the gimp off all the time (you'll still do significant damage) but when you do, you'll feel satisfied!