You know your shit golden, but saying a feral is at the mercy of your opponent after opener is just crazy. Infected wounds allows you to kite melee targets, between trinket and shifting slows you can plow down any caster. Only difficult tasks are hunters whom you don't have terrain advantage on.
You open on a hunter, he scatters. Gets some distance, and kites you to death. Your trinket forces an Intim, Disengage, or his trinket, but he still wins. A rogue is toast in a similar situation, but he can at least pray for an Evasion dodge on Intim, and SS the disengage.
You open on a mage, he novas, you are toast. Trinket nova, blink. If the mage trinkets the snare, he's got a good chance of kiting you with Arcane Blast + FB + CoC.
You open on a Lock, he fears. You trinket, he refears, and can usually finish up the job on the first tick of Doom. I nailed a nasty combo last night on Lle (disc priest) that did about 1700 damage in 2 GCDs out of a fear (Soulfire, Corruption tick, Doom tick, SB Soulfire, Conflag) as an example of the damage to overcome vs a 1.8K HP lock with SL and Healthstone.
You open on any healer...he heals through it. No faking necessary.
You are correct about them having the edge on Wars and Rogues (kiting the evasion, thorns the SS), but kiting Enh and Ret doesn't do much when they can keep you in combat/dotted to prevent restealth, or just top themselves off like you never opened.
Without gouge, kick, arcane torrent or SS, feral lacks the control I was speaking of. The globals you end up wasting on powershifting are too valuable in such a bursty bracket. You end up half dead by the time you get back on your target.