Starting Colonists Help
You want a healthy colonist, no disease.
Closer to 20 is better, above 40 I start avoiding them
No negative mood traits like depressive, no pyromaniacs (one or two in a colony can be fine but you’re playing with fire), no greedy, no gourmand, no pure negative trait. In the positives, look for Tough as it is the single best trait, sanguine/optimistic for mood, nimble, happy-trigger, quick sleeper, great memory, industrious, jogger, iron-willed are all good, ascetic is also interesting for a royal.
Work Type and Passion
You’re looking to be able to do everything, and have a burning passion in everything. Not easy with 3 pawns, but to me construction is essential, preferably on two of them, planting too, you’re most likely going to cut a lot of wood early PLUS do field work to feed yourself, and if you don’t have a really good planter or two average ones things are gonna progress too slow. You want one passionate cook, probably one good researcher (don’t make him have another important/time-intensive job because research never stops), all three capable of doctoring and firefighting if possible, more than zero is obviously necessary
Artists and crafting, tailoring etc can wait for a while, you don’t really need to look for it in the first 3. Construction, Cook and Plants is key, having a miner will be important early IF you’re making an underground base OR you’re using a lot of steel (with biotech mechs for example). Otherwise, this can wait.
So yeah, the absolute ideal start is youthful, healthy colonists that have some combination of tough, sanguine, trigger-happy, industrious, jogger or quick sleeper, and cover all of the bases with their work types, making sure you can construct your base fast, your researcher isn’t your cook or your plant worker, and your cook isn’t your plant worker either, as this may get annoying because all three works require too much time.
Someone refusing to do something like hauling isn’t bad, as long as they make up for it in some other areas. The only crippling thing is unable to fight (avoid at all cost in your starting trio), unable to doctor and firefight.
If people mentally break often and don’t have mental break traits like depressive, volatile or neurotic, the solution isn’t in the starting draft but in the way you’re running your colony. Look at what’s making them mad in the needs tab and fix it, and make sure you give them reasons to be happy too (spatious/pretty/rich environment, good food, comfortable lodging, drugs if needed, etc)