So you want to play a tengku

Scarterran tengku are sort of an amalgam of the tengu of Japanese folklore, kenku from D&D, and the ferengi from Star Trek Deep Space Nine with a dash of the Raven the trickster myths of northwest Native American folklore.
That's kind of a narrative mess I suppose, but it gives you a wide variety of options. Tengku get a bonus on Commerce rolls and have a stereotype for being wheelers and dealers but you don't have to play your tengku that way. Tengku are still individuals and PCs often vary from the stereotypical mold of their cultures a lot. A tengku character can fit into almost any character concept.

So you want to play a warrior who is also a tengku?

Armored Tengku with potion pouch by Zeta Gardner

Tengku have a bonus on all non-magical Dexterity rolls. That is huge boon to combat as you'll hit more often and be hit less often. Tengku start out with one fewer "Bruise" level and have an increased vulnerability to blunt force trauma which can situationally be a very problematic weakness but on the whole, the Dexterity bonus more than makes up for this increased vulnerability.
Tengku are pragmatists and tengku warriors are no exception. They fight to win and they will use any clever or dirty tactic they can, chivalry be damned. Once in a while, a tengku warrior can use his talent for mimicry to help set up an ambush or trap.
Tengku are a talkative lot, but tengku warriors do not generally buy into the warrior culture of boasting, especially when they are not fighting under the tenets of chivalry.
Tengku warriors are not cowards but neither are they fools. They prefer to fight defensively favoring ranged combat as their first choice and rarely fighting close combat without a shield.

So you want to play a Rogue/Expert who is also a tengku?

Tengku are a good fit for expert characters. Even if a tengku is uninterested in pursuing a mercantile career, they usually gravtitate towards careers that favor brains over brawn.
Tengku are no better or worse than humans when playing a more scholarly expert type. Tengku might be relatively short lived but they are also fast learners and naturally curious. Their keen senses and tendency to down to earth wisdom makes them good wilderness experts.
Tengku are natural for the rogue archetype. They are commonly smooth talkers and they are often but not always motivated by greed. Their mimicry ability is very handy to con artist types.
A tengku's Dexterity bonus helps for sneaking around, picking locks and picking pockets.

Tengku #7 camo version by Zeta Gardner

So you want to play a mage who is also a tengku?

Neffrey the tengku warlock by Eron12 with Heroforge

A disproportionately high number of tengku become mages. You don't see many tengku sorcerers but they have their fair share of warlocks and more than their fair share of wizards.
Tengku are unlikely to be rune casting wizards or Body Wizards but many of them are Folk Magicians, Aesthetic Hermetics, and Aesthetic Hermetics.
Tengku have a robust musical culture at least on par with humans, and many tengku mages are bardic mages.
Tengku commonly favor the school of Transmutation because while the school has many useful things that tengku like, above all, it lets casters fly and whether they admit it or not, most tengku possess a yearning to fly deep down. Illusion magic, Enchantment magic, Divination magic are also fairly popular among tengku mages. The schools of Conjuration and Necromancy are somewhat underrepresented among tengku mages.

So you want to play a divine magic caster who is also a tengku?

Tengku as a whole are not known for their piety. That said, a tengku that does live the pious life is going to have to deal with more obstacles to their pious lifestyle both from other tengku and from society at large. This means a lot of pious tengku go through a series of challenges that galvanize their faith which often results in them developing the will and faith to become theurgists.
Tengku theurgists are hard to pigeonhole because most of them are non-conformists within tengku society, so by extension tengku theurgists could be affiliated with any religious order. The slim plurality of tengku priests and priestesses are affiliated with Phidas with the Rovers and Children in second and third place. But pretty much every religious order occasionally sees a rare tengku among them.