Stat weights for fire mages have been changing recently due to the T21 bonuses. Essentially, you want to combust as much as possible with T21, so the Kindling talent synergizes with it much more than the Cinderstorm and Meteor talents. Kindling prefers crit over other stats, as it only works on critical hits. You have a relatively large amount of haste/mastery, relatively low crit, and no T21 bonuses, which tends to favor the Meteor build. The reason why you're given different stat priorities by different websites is due to the fact that your best stat is heavily dependent on your situation and talent build, and they're trying to give a general answer instead of what is best in your specific situation. When in doubt about which stats are best for you, sim yourself:
https://www.raidbots.com/simbot
However, I would start stacking crit, because it is the best stat in combination with Kindling and the T21 set from Antorus. Given your 3 Preignited relics, I would sim yourself with both Kindling and Meteor, and use whichever sims a higher DPS.
Something to consider is your legendary choice. From your logs, it looks like you've consistently been using the bracer and belt. On the fights where you lust at the start (Hounds, Varimathras, Imonar, Coven, Aggramar), the shard/bracers can be a better choice. This doesn't matter as much on your Hounds, Imonar, and Vari parses; which all lasted less than 5min, so you would only have 2 lusts. However, on longer fights, like your Coven and Aggramar parses in particular, you would have been able to fit in 3 lusts using the shard (your TW at the pull, someone's 2nd TW/lust for you at approx 2min-4min in, your TW 5-6min in; note that this can get wonky and requires some coordination if these is more than one mage in the group is using the shard).
For your opening rotation, you shouldn't be using Combustion until the boss is at approximately 91% to 90% HP, as you are currently using Firestarter. With Firestarter, you want to open with pre-potion + Pyroblast (before pull) -> Fireblast -> Pyroblast -> Pheonix Flames -> chain Fireball + Pyroblast until you get a bracer proc or the boss reaches 90% HP. If you get a bracer proc at 90%-92% boss health, start hardcasting the Pyroblast and then use Combustion when the cast is nearly over. Once the boss reaches 90% you want to use Combustion. You don't want to use Combustion before that point, because you're wasting any value of Firestarter if the boss is above 90% while your Combustion is active. You also want to use Scorch instead of Fireball during Combustion.
The last thing that I noticed is your CD usage. Make sure that you are using a Potion of Prolonged Power before your tank pulls, and one before a Combustion is used. You're only using Tarnished Sentinel Medallion 1-2 times per fight, when you can be using it 2-4 times. You want to use the Tarnished Sentinel Medallion whenever both it and your Combustion is off CD, and save it for when your Combustion is off CD. Keep in mind that you'll probably be keeping the Tarnished Sentinel's Medallion for awhile, as it's the 3rd best trinket for fire mages, assuming maximum trinket item levels, after the Aman'thul legendary and the Acrid Catalyst Injector. The nice thing about the Meteor build is that it keeps both the Tarnished Sentinel Medallion's and Combustion's CDs lined up. Make sure you are using your troll racial whenever it's up for a combustion rotation; you should be able to use it on every other Combustion. In summary, you want to use your Combustion whenever it's off CD. You want to save the rest of your CDs for Combustion, and activate any that are ready just before you start a Combustion (potion, time warp if using the shard, troll racial, Sentinel Medallion, etc). The more CDs you can combine together, the more DPS you will do.
Let me know if you have any questions!
