"Väktaren" can be either male or female. "Vakt" is the general word for "guard"; "väktare" is a certain professional role in Sweden - a guard hired by an authorized security company, which has certain legal implications.
(A word of advice: professions/occupations are always, or pretty much always, en-words. En polis, en väktare, en programmerare, en lärare, etc.)
No. The only job I can think of that has it like that is fyrvaktare, a lighthouse keeper.