Are any Swedish and Norwegians here?

I am Swedish. Also I know some Norwegian and I am very good in Danish.

Only to certain extent - I really don´t know Norwegian slang and use very little myself in Swedish, but let us try I can always ask people around me who know more.

Why do you want to know slang for a research project?

Him
just give me a list of the words you need and I`ll translate them.

The words you gave me are not really slang, but part of a normal language. Do you want them to be translated like that or in slang?
Then if slang it depends on the speaker`s age and also the group the speaker belongs to. I´ll do my best S stands for Swedish, N for Norwegian

tough guy S tuffing - modig (courageous) - djärv (bold)
N töffing - töff karl
tomboy S pojkflicka
tough girl N töff jente
S tuffing but I don´t really feel it is good in connection with a
girl
tough woman S+N there are several words depending on her caracter
guy prone to fighting S slagskämpe - not slang - can only be used about men
girl prone to fighting cannot find any word for this as a rule women were not prone to fight.
woman prone to fighting see above
delinquent girl S småbrottsling
delinquent boy S småbrottsling
cool guy S tuff grabb
cool girl S tuff tjej
gangster S+N gangster
punk S+N punk
wild girl S tuff - framfusig (pushing, pert)
wild boy S - see above
powerfully-built male S kraftfull man N kraftig bygget karl / mann
powerfully-built female S kraftfull kvinna/tjef N kraftig bygget kvinde/jente
strong guy S tuff/ självsäker (self-confident) stark (strong)
N stärk mann/gut

strong girl/woman S. see above
N. stärk jente/woman

fjortis is someone who is 14 years old. Fjortonåring.
It is very difficult to use slang and other expressions if you don´t know a language very well. As I do not know anything about in what connections you want to use it it is hard to help you.
You have to explain the age of the speaker, what area s/he comes from, if the person is living in a big city or in the country side. Is the person a Swede or a Swede with foreigh background or a foreigner speaking Swedish.

Hi, I understand whom you are referring to, but again the young people whom you see in the streets come from all kinds of back grounds. As a rule the better educated and the better well behaved young people use very little slang, then you have gang-teens and I must admit I have no idea about their language, which again depends on their gang and what part of Sweden they come from. Young aduls usually have left the teen age laguage behind and if they use slang it is another type than the ones who are teen agers. There is a generation gap between them language wise.

I am sorry but I really don´t think I can help you as everything is too general.

Translattion is a very difficult thing and often mistakes are made.
Was reading a book were the word trasformation was translated to wig.
How about this one.
Original language
The father forbid his daughter to marry a man who had large debts-
translation The father forbid his daughter to marry a man who had large shoulders.

cool guy - kul karl kul=fun and is a rather old slang or daily language word
karl = man and is hardly used by young people
cool boy - kul pojke pojke= is a correct word for boy and grabb would better amongst young people, but the combination kul grabb is no good
cool girl - kul tjej
(or 'kul flicka', but that's more like a little girl)
flicka is the correct word for girl and tjej is the modern word amongst young people for girl. Has nothing to do with the age.

-yrhätta,= is not slang but means a girl who is running around always being busy
argbigga,= is not slang means shrew, vixen
"näbbgädda" = means garfish or daily language hussy minx and is an expression I haven´t heard for years
"vildkatta"= is no slang either it is more a tomboy