Dots snapshoting has been removed. Meaning all dmg increase buffs (trinket procs, Dark soul etc) will affect all active dots on all dotted targets. So pop dmg cooldown once the target is dotted for max uptime of dmg. Altho Dark soul can greatly help with getting dots off.
U do not need to reaply the dots when haunt hits for them to be affected.
And lock its not FOTM. Altho its absolutly a tor tier caster charr. FOTM now is melee (not monk tho).
Generaly playstyle tips: go to the affi guide for 5.4.7 i think its named. Basics is still the same. U can vary glyph's /talents a bit more now. And u gotta make sure to use Soul Burn -> Haunt at 100. And not to use soul swop more or less like ever. Else then that pritty much the same. A bit dumbed down tho.
Maintaining 10 stack agony's is always the top priority. Siphon life glyph is negligible in short term situations, but keeping your dot uptime as close to 100% as possible has always been the ideal situation for affliction.
Other major tip was as mentioned; try to only use your shards for Soulburn: Haunt. It costs two shards each time you do it so you need to manage your shards effectively.