Can you say "szőkek"? If not, why not?
"Szőkék". Not. Because adjectives in front of nouns, modifying the nouns, stay singular.
As a native speaker of American English, the phrasing "in the bus stop" sounds exceedingly strange to me. "At the bus stop" would be much more natural. Is this typical UK usage, or is it a translation error?
It's a translation error.