This is a Thief Guild following the format invented by Velexiraptor, as follows:
Level 1: Gain 2 abilities at rank 1
Level 2: Rank up an ability you have, then gain a new ability at rank 1
Level 3: Rank up 2 abilities you have
Level 4: Rank up 2 abilities you have, then gain all abilities you don't have yet at rank 1
Hit Die: d6 (if you use those)
If you use weapon proficiencies, you are proficient with greaser weapons - that is, practical urbanite stuff.
Starting Equipment: Comb, Jumbo tub of thick grease, hand mirror, spring-loaded knife, stylish outfit, a narrative-and-setting-appropriate mode of transportation (horse, motorbike, T-Bird) that only performs properly for you.
Skills (2, d6): 1. Dance, 2. Smooth-talk, 3. Vehicle/driving/riding skill appropriate to your original mode of transportation, 4. Streetwise, 5. Gambler, 6. Bravado
✧: You may dance-fight. You must not be encumbered or have anything else hampering your movement, and be able to hear some kind of appropriate and familiar music to quicken your soul. A group of people clicking fingers in unison works in a pinch, as does hallucinatory music. You get +2 to your AC and Attack against foes that cannot match your smooth moves.
✧✧: You may add your dex bonus to damage rolls (instead of strength) while dance-fighting. If you are hampered or the music stops while you are dance-fighting, you retain the benefits for two more rounds.
✧✧✧: You can lead a small group of people to dance-fight, though they are subject to the same restrictions and must be able to see and hear you. You can always hear your theme song if you concentrate.
2. Home Turf
✧: Declare a Home Turf no larger than a small town. You always know the fastest route through your Home Turf and can always find a place to lay low there.
✧✧: Once per week you can declare you Know A Guy from your Home Turf who could conceivably assist with the current situation. The GM rolls that person's Reaction when they are next encountered - they may require appeasement or refuse entirely.✧✧✧: Gain a Reputation in your Home Turf as befits what is known of your actions. Everyone has heard of you (though you are not always recognised on sight). Discuss with your GM what this reputation is and what effects it will have. This reputation can be changed over time through great effort.
3. Percussive Maintenance
✧: Precisely strike an object that is entirely mechanical and entirely comprehensible to you, with a body part, after studying it for at least one round; this makes it immediately perform as you would like, within the realms of physical possibility. You can ignore one of these underlined clauses but if you do, you only succeed on 2-in-6. You may not retry unless you meet all clauses.
✧✧: You can now ignore two underlined clauses, but if you do your success rate is only 1-in-6. If you fail, you may retry once without having to meet all clauses.
4. Fast Hands
✧: You can draw and make use of the item in your very first inventory slot even if surprised.
✧✧: Gain an extra two quick draw slots. Get the ✧ benefit for your second inventory slot also.
✧: With 10 minutes of work and the correct tools, you may style your hair beyond the ken of mortal man. Hats/helmets/etc will ruin it. You may sunder your hairstyle to reduce damage from an incoming attack by 1d6, similar to a shield; you gain advantage on attack rolls against whatever ruined your hair until you hit them.
✧✧: When you sunder your hairstyle it reduces incoming damage by 1d6+2 points. You gain advantage on the attacker until you have hit them twice.
6. Magnetic Personality
✧: When Reactions are rolled you can adjust the result to be one point more favourable if you are prominently visible and groomed properly. (Not all creatures have variable Reactions.)
✧✧: While you are in a location where you are regarded well, you can draw a room of people to come to your aid if you succeed on a Charisma check. They are not much more willing to endanger themselves than usual. Misusing this ability may cause people to dislike you.