I tried my hand at adjusting the warforged race. Here's what I came up with:
Warforged (Main Race)
Constitution +2
Living Construct: You are immune to disease. You do not need to eat or breathe, but you can ingest food and drink if you wish.
Instead of sleeping, you enter an inactive state for 4 hours each day. You do not dream in this state; you are fully aware of your surroundings and notice approaching enemies and other events as normal.
Self-Stabilizing: A Warforged that is reduced to
0 or fewer HP has advantage on death saving
throws.
Languages: Common and one other language of
your choice.
Mithril Forged (Subrace)
Dexterity +1
Size: Medium.
Speed: 30 feet.
Composite Plating: You gain a +1 bonus to Armor Class.
Weapons Training: You gain proficiency in the longsword, shordsword, shortbow, and longbow.
Nimble: You gain proficiency in the Acrobatics skill.
Adamantine Forged (Subrace)
Strength +1
Size: Medium.
Speed: 30 feet
Composite Plating: You gain a +1 bonus to Armor Class.
Heavy Weapons Training: You gain proficiency in the greatsword, greataxe, halberd, and maul.
Adamantine Body: You have immunity to Critical Hits.
Clunky: You have disadvantage on Dexterity (Stealth) checks.
Scout (Subrace)
Wisdom +1
Size: Small.
Speed: 40 feet.
Stealthy Tracker: You gain proficiency in the stealth and survival skills.
Stowed Weapons: You gain proficiency in hand crossbows and shortswords. In addition, you have special compartments in each arm, one carrying a hand crossbow and up to 10 bolts, and the other a short sword that can be extended or retracted directly from the arm. These weapons cannot be disarmed and are considered part of you. You gain a +10 bonus to any check to conceal these weapons. These weapons can be swapped out for newer, magical crossbows or shortswords over a short rest.
Final Messenger: You can cast the animal messenger spell once using this trait without requiring the components or animals present. Instead, the messenger appears as a tiny flying construct produced by your body. You cannot use this ability again until you finish a long rest.
If you are reduced to 0 or fewer HP, you automatically use this ability, even if you have already used it today.