This is my opinion.
I'm not a fox player, and it will take alot of playing before i ever commit to being a fox player; becaues being a good fox player isnt really about what YOU do, but what you avoid.
Unlike alot of games (read, a majority of the competitive fighting games), the reason why fox is top tier is because of what he himself does to other characters, not what other characters cant do to him.
Without all the wraparound wording, what im basically saying is; being a good fox means you can avoid getting *****.
Why do i say that? Because every fox "main" under the sun can do most of the techs they need to do, SHDL, waveshine, drillshine, etc etc. Hell, even the garbage people who couldnt beat their mom with fox (read: me) can do that stuff. But the reason why people wind up being mediocre with fox is because they dont know how to not get grabbed, and how to not get comboed; which is what it takes to be good.
Somewhere around half the cast can chaingrab fox from 0-death. 90% of the cast can COMBO fox for 0-death (although you have to look at ridiculously good people to find it in lower tiers, it IS possible). What that means is, it doesnt matter how man JC shines you can do on somebody's shields, you have to know when and where to do it so you dont get grabbed.
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Basically it amounts to this; 90% of the people you play in this game are mediocre fox players. Heck, im a mediocre fox player. Bare minimum, all you need tech wise is some form of lasers, grab, and upsmash; everything else is icing on the cake. What makes you a good fox player is when you know how to do all the stuff and not rocked, because EVERYBODY knows how to fight a fox, and everybody has things they can do against fox, usually resulting in fox getting gimped or something of that effect.