Many questions. Please share your oppinions!

I noticed Stone Edge, Blizzard and Hyper beam is either faster or has faster cooldown time. I wouldn't know for sure though.

SW dragonite works on both offense and defense, not really any bad moves on him.

Power up legacy movesets if they are good for defense and you need defender, otherwise just keep.

I powered Gengar with SC/SB to 30 but mine was above 80% IVs. Good attacker.

I'm sure there is some use for him, not as good as a ground type with bulldoze but it could do something.

Heracross is regional, only Photoshop screenshots say otherwise. It is below a certain latitude mainly in Central / South America. Only US locations to get them are Southern Florida and Texas border.

The dodge windows and animation times have had small changes on most moves, bubble and confusion have different damage windows which need to be learned.

I just got a dual fighting move poliwrath, haven't tried him yet. But it's important to have a dual fighting move Pokemon for Blissey / Snorlax. Try for Primeape too, he is weak defensively but puts out a bit of damage.

Finally, Magneton has always worked as an attacker / Prestige Pokemon. Just might work on things other than Gyarados now.

1 - your dragonite is still good, prety usable on offense, but not the best one.
2 - To lvl 30 only, great defensive moveset, but so so IV.
3 - If the IVs are good, SURE, SC is great on offense now, if SB is Shadow Ball is even better, but Sludge Bomb are very good on Gengar anyway.
4 - Nah, go search for a better K9.
5 - The reports are probably fake, we haven't seen any reliable video (is important to be a video of a mobile phone) of someone with heracross outside the exclusive region yet.
6 - Probably, SB is very slow
7 - PWrath is a good mon overall, better than politoed, so yes, i'd choose him, and if you dont have any good counter to blissey.... any help is valuable.
8 - Nice attack and defens stats and nice moveset, but TERRIBLE stamina. You can use him, is kinda good but Jolteon is way better.

Hope that i could help :)

1. Steel Wing Dragonite. Pretty good on offense. On paper worse than Dragon Tail but it's still good especially if you dodge and you're able to get an extra attack, because now it's much faster and actually has the highest DPS of all quick moves before any adjustments (attack stat or STAB etc).

   It's good on both offense and defense, it's just not as good as Dragon Tail in most situations.

   Same with Dragon Pulse. Not as good as the new Outrage but still a strong move. Many people are overreacting about the new moves. Yes Future Sight is a better Psychic, Overheat a better Fire Blast et cetera. The latter moves are not trash, they are simply worse in comparison, like the old attacking movesets compared to DB+DC. Still really good, just not as good as the best.

2. At level 30 it'll have 2370 CP compared to the maximum of 2500 at 30. If that's a deal breaker for you, then don't. It's also usable on offense too. He can still sit in gyms and is still a great attacker, just requires some extra power ups. If you're stingy about dust/candies then don't power it up further.
3. Doesn't have any super favourable matchups (or not that I know of) but'll do huge damage against pretty much anyone. People were powering up the old PC/P Alakazam, and this Gengar is pretty much on par with that moveset, so yeah, it's worth powering.
4. Dumps on Magnetons which are double weak to ground, which is the same multiplier as having STAB and SE. Good luck finding a Magneton defending gyms though. Bulldoze is still a suboptimal move, but now it won't lower your overall DPS compared to not using it, so that's nice.
5. Can't say for sure. Maybe people lie. Maybe Niantic could spend a few seconds making a tweet confirming whether or not Heracross is a regional exclusive.
6. Maybe the damage does come sooner, but I don't remeber the old value, so again I can't say for sure . Some moves, the most obvious one being Blizzard have had their damage windows changed - or whatever the correct term is for the time between using the move and when damage is actually dealt, so it could be possible the same happened to Solar Beam.
7. Rock Smash is worse than Counter, and Machamp has about 20% higher attack than Poliwrath. It does have a resistance advantage against ice pokemon, since fighting is super effective, but other then that I don't see much type synergy realistically speaking, but I still think it's better than Politoed, since you have the potential for a pretty good moveset (Rock Smash + Dynamic Punch), while Politoed's aren't that good besides Bubble + Hydro Pump which Poliwrath can also get anyway.

   If you want to fill your dex, go Politoed, if you already have a good fighting type attacker, if other fighting type attackers are rare (Mankey / Machop) and you need/want one, go with Poliwrath in my opinion. Even if you do get an undesired moveset, what could you have done with Politoed instead?

8. Magneton has terrible stamina so I don't think it's ever going to be something you take with you into a level 10 gym, but it's steel typing helps offset that low stamina in 2 realistic situations, against ice and flying type moves, since there's a few pokemon that have ice + water typing, notably lapras.

   It has similar stats to Jolteon but Jolteon has 30 more base stamina which is about 20 extra HP around levels 25-30, and HP works against all moves, whereas steel typing only helps against specific types, so in most cases you'd rather use a Jolteon instead.

   To make matters worse, Jolteons are mainly used for prestiging against gyarados, and none of gyarados' moves are resisted by steel, so magneton's advantage of it dual type is rarely usable.

   If you already have a Magneton with Zap Cannon, sure use it, but it's not going to be that much better compared to a Jolteon, and if you don't have one, I wouldn't say it's worth trying to get one other than to fill your Pokedex when Jolteons are a dime a dozen.

In regards to Poliwrath, he will be a great counter to the Tyranitars that are getting ready to be in gyms all over the place. With fighting moves he will hit him like a truck and have stab while his duel water typing will resist the dark, rock, fire, and steel moves of Tyranitar. Even if his moves are split between water and fighting it should still be an easy takedown.

The straight fighting mons will still have to eat his fire and steel attacks for full damage.

SW/DP is lower DPS than all the movesets with Dragon Tail, as well as all the legacy movesets with Dragon Breath. I'd still use it for defending, but it's not going to perform as well as Dragon Tail for that purpose.

For straight up DPS the rankings go:

DT-Outrage
DT-Hurricane
DT-Hyper Beam
SW-Outrage
DB/DC
DB/DP
DB/HB
SW/DP
SW/HB
SW

"Please, don't talk about DB. I don't have it, I can't have it."

Haha, love it! (Needless to say I'm in the same boat)

Good luck. :)