Hi! Actually, we don't have a truly negative word like it seems you have in Portuguese for a street vendor. Words like hawker, peddler, vendor, huckster, etc are neither negative nor positive. You could try pusher, but this doesn't have a negative meaning towards their products, more towards their attitude (a very pushy, obnoxious person.) Someone might have a different impression of these words, but we don't really have a set impression like in Portuguese for these words. Also, hawker, peddler, vendor, etc, aren't used with another word; they are used by themselves. "There's a hawker down the street selling knickknacks. Want to see if he has anything we like?" Sorry I can't help more!

I don't know, "hawker" can mean an aggressive vendor, or a vendor who calls out his goods on the street, "hawks" them. "Get your fresh vegetables!" But it's just "hawker" not "hawker vendor"... "sketchy vendor". Something that is "sketchy" is like a sketch, its roughly drawn, maybe not trust worthy, you don't really know what's there, like a sketch doesn't necessarily accurately describe what's sketched. You could say "grey/gray market vendor" which is like not "black market" illegal, but maybe, grey... "huckster" or "peddler" are very similar to "hawker" but not necessarily implying that you wouldn't trust them... you need an adjective to really get that across I think. Like "less than trustworthy", "less than reliable". You could say "sharky" maybe...

Not really - a smuggler is someone who imports something illegally. 'Black market' as an adjective is a better option.

I haven't actually ever heard someone called a "hawker" in the midwest of the USA. I do think of huckster as having somewhat negative connotations- just that the sales rely on their aggressive sales skills more than their product. Since dealer often means illegal drugs, dealer definitely has a shady connotation. Street or sidewalk dealer or peddler seem like reasonable options. And in the US we don't say dodgy but we'd get it and think you're cool.

"Street dealer" is the first term that comes to mind.