One way to conceptualize it structurally is that the dash works like a colon would in English. "These men: actors" (of course this seems very strange, as you don't structure sentences like this in English, but bear with me). First you are defining an object: "These men", and then you are describing an attribute of the object: "actors". And this way of thinking makes it clearer for an English speaker how it is to be said in spoken Russian too; when there's a colon, there's a pause!
It seems like it should actually translate into: "These are actor-men", instead of: "These men are actors". Which sounds weird. I'm Polish, so I use a language with a vocab similar to Russian and with small differences in sentence construction, and If anyone were to describe someone's vocation this way in polish, people would give them a strange look, to say the least. So can somebody, who actually is Russian, confirm that the above construction does exists and is currently used by the Russian people, and isn't just some mistake of, let's say: copying the sentence structure from a Mandarin language course?
Unfortunately I can't speak to Polish since I have never studied it, but this is a correct Russian sentence and the translation "These men are actors" is correct.
1) The symbol here, the longer hyphen, is called a тире, and it's considered a punctuation mark. Note the spaces between the noun, тире, and noun. This is the simplest way to say "X is Y" in Russian. The тире serves as sort of a half pause between the words. There is at least one verb, являться, that means "to be", but it requires instrumental case and is typically reserved for higher level speeches, technical/scientific documentation, etc.
2) The "normal" hyphen used in words, the дефис, is essentially a spelling character that combines two words into one, like you mentioned. There are no spaces between the words and the hyphen, it's essentially inserted directly between the two words. When you're describing words like that, it would be said that they are written "through" a hyphen (писаться через дефис).
3) Also please bear in mind that if the demonstrative "это" is used (in this case, эти), then the phrase would be "these ...", which would not necessarily be a complete sentence. For instance, if it were "Эти мужчины-актёры", then that would just be "These men-actors" - that by itself would only work in response to a question starting with "Кто".
Check out this site for some spelling rules: http://www.russianlessons.net/grammar/spelling_rules.php In this case, a ы can not come after a к.