MCH rotation advice (leveling/dungeons) 60-80 ?

So for leveling mch from 60-80 what would be good to use to help me level well and also use in end game ?

You already have most of your endgame rotation with level 60. What you'll get for your single target rotation are only some upgrades to your current skills (Clean Shot upgrades to Heated Clean Shot; Hot Shot turns into Air Anchor, Automaton Queen replaces Rook Autoturret), so nothing really changes. The only 'new' thing will be Barrel Stabilizer, an ability to rise your heat gauge by 50 - which is nice as it allows you to enter Hypercharge faster and more often.

For your AOE Rotation you will get Flamethrower with 70 and Bioblaster with 72 - which helps to literally melt down those dungeon mobs. And Barrel Stabilizer helps here too, of course, for more Auto Crossbows.

So what should i be using at 60 (haven't played mch when first came out in heavenward) got to 60 and swapped to another class before Stormblood came out

Going simple

Single target:

-You usually pair Reassemble and Drill when available
-When Drill and Hotshot are not available, do you 1-2-3 combo. Drill and Hotshot don't interrupt combos so don't hesistate on prioritizing them.
-When Heat is at 50 or more and Drill/Hotshot are not available within 10s, use Hypercharge and HeatBlast+GaussRound/Ricochet inbetween.
-If you have a combo pending, you can't align Drill, Hotshot and a full Duration of hypercharge. The combo will drop so be carefull about that.
-Wildfire is a cooldown you must use right before Hypercharge, so the target will take additionnal damage at the end of its duration, according to the amount of GCD you used during that time.

-When battery is at 50, you can summon the turret, there's no gain worth to use the turret above 50 battery. Just note that it will consume all the battery, duration extending accordingly.

When there is 3 or more ennemies:

-Later (lv72) on you'll get an ability which cooldown is shared with Drill, Bio-Blaster, it's the highest priority.
-At 50 heat, prioritize using Hypercharge and Auto Cross Bow when available.
-When Bio-Blaster isn't available within 10s and you're not at 50 Heat, use flamethrower. (lv70)
-When nothing else is available, Spread Shot.