The basic rotation is the same at lv 50 as it is at 70. Eye>Path>Path>Repeat. Use FC before you go over gauge cap. Theres nothing fancy going on. If you need enmity, replace Path combos with Butchers combos as needed.

Theres really not much to 'plan' except your zerk window. When Zerk is coming up, save some gauge to use more Gauge skills (FC, Decimate, infuriate) while zerk is up so you force crit an FC instead of a heavy swing. But if you don't, its lv 65 or whatever dungeon. No one will care, and it wont matter. At 70 the gauge comes for free so you wont even need to 'prepare' before a zerk window anyway.

SE has gone to great lengths to simplify every job's rotation in SB and have succeeded. HW war had to really prepare and plan minutes in advance, but nowadays all 3 tanks can basically just use their DPS abilities on cooldown and perform a simple combo rotation and your nearly home.

Don't sweat it. Leveling is very shortlived and basic rotation will get you 90% of optimal as it is. Optimization at 70 is more about aligning your damage with party buffs than some complicated rotation to manage.