Reaper DPS DPS Melding, Stat Priority, and Consumables — Endwalker 6.55

1. Weapon Damage;
2. Strength;
3. Skill Speed to preferred GCD tier;
4. Critical Hit Rate;
5. Determination / Direct Hit Rate.

Weapon Damage and Strength will almost always produce more damage than focusing on substats.

Skillspeed is a hard stat to pin down because it comes with a lot of caveats. For Reaper, there are very few interactions that it has with their kit since most heavy resource generators come on a strict cooldown. However, it can change things like how far into your GCD you are when Arcane Circle or Gluttony comes up, or it can allow you an extra GCD before a boss phases. The currently preferred GCD tier is 2.49 as it allows you to Arcane Circle nearly on cooldown and allows for comfier GCD times in current Savage fights. 2.5 and 2.48 are also optional GCD tiers if slower or faster fits your playstyle.

Critical Hit Rate is currently better than both Direct Hit and Determination. If you are unable to meld Critical Hit, then meld whichever stat is currently the lowest between Direct Hit and Determination. Alternatively, you can use the gear planner made by Jahadaunt and Makar to evaluate your gear options. You can find the planner here: http://bit.ly/Gear-Planner. (Note: Make a copy of the gear planner to use it and close out of it afterward to lessen traffic on the planner.)

Potions (tinctures) in FFXIV are fairly straightforward. Simply use the highest tier of Tincture of Strength that you can afford because the highest tier offers the best stats.