1) Don't see any issue with powering up the Entei to final breakpoints against Jynx/Pinsir (whichever is higher), provided RC isn't an issue.
2) Any chance you could pick up a horde of weather-boosted Eevees and pray for RNG to provide you with the Flareon you're looking for?
3) A Charmander Community Day could very well be a month-and-a-half away, so I'm not sure if investing (heavily) in that line right now would be the wisest move.
4) Don't dismiss Typhlosion so easily. It has access to Overheat, for one. And perhaps more importantly, it has access to Shadow Claw, which has coverage against both Jynx and Metagross. Its stats aren't bad either (in fact, they're the same as Charizard's).
5) Arcanine isn't as bad as you might think he is; the fact that yours has legacy Flamethrower only makes it a better option. Although I do prefer Arcanine as a pseudo-electric type.
6) Regarding Houndoom, you're right about his usefulness as a Dark-type, but this still leaves him viable against Jynx and Metagross.
7) Leave Blaziken as he is, good DPS but glaaaasssy.