B/FT Arcanine for dodging

No, bite is way worse than fire fang in practical terms. The lack of STAB along with mismatched type against what you'll be fighting against (i.e. Grass types), you'll be losing out on a 1.56X multiplier (or in other words, you'll be dealing only 64% of Fire Fang damage.) It holds its own against Exeggutor however as it is weak to Dark moves as well.

I'm also hesitant to power a 82 IV as well, you probably have a higher IV Flareon than this Arcanine? Flareon does better than Arcanine, if you dodge properly, as you mentioned.

I have a FF/FB and a B/FT both 91% 2585 cp and powered up to level 34.5. I primarily use them against Eggys and B/FT is the undoubtedly better mon for dodging. I can takeout more eggys with the B/FT then I could with the FF/FB. When im in a hurry I use the FFFB and when Im taking down a diversified level 10 gym I use the B/FT. Bite is horrible on defense but on attack its a star. You can get 2-3 more bite attacks in between dodges then with FF which combined with the faster charge yields a way way higher DPS with bite against Eggy(Dark is SE on Psycic). Against Venusaur the gains are smaller and closer together.
82% is a strong IV and you have your ideal moveset thats very valuable. I think the game is currently being much more stingy with tier 1 IV's so getting something better with the moveset you prefer may take you a long time.
Its already almost level 30 so Id definitely power that up to there. Im a tightass with my stardust so I would recommend holding off on any power ups past 30 tho. Gen 2 is right around the corner and a superior fire mon may be released then. If there isnt and you still love that puppy power it up some more.

I have 2 Arcanines aswell, one with FF and one with Bite. Imo Bite is superior quick move, its a lot faster, it generates a lot more energy, easier to dodge, has better type coverage (nothing really resists dark atm).
Dps might be a little bit smaller than stab Fire Fang if you just stand still and spam attack, but i really prefer to dodge stuff.