1. Is he over his head financially?
In over your head - think 'drowning', if you are 'in over your head' the situation is so large / deep that you cannot cope & risk failure (death).
Another similar idiom would be "is he biting off more than he can chew" by taking on too large a responsibility.
2. ‘Ladies’ is a euphemism for females sent to compromise the opposition.
I would think 'ladies' in this occasion is 'prostitutes' or 'women of ill repute' sent to get information (via 'pillow talk') from the opposition.
eg. Think of two large companies, sports teams or warring nations - one uses 'loose women', to get information out of the others male workers/ players/soldiers. Not openly, but as spies.
3. That’s is, buddy, throw me a few crumbs.
Sarcastic. "Throw me a few crumbs" - "just give me what is left", "take all of the good 'things' for yourself and leave me almost nothing"
4. Sure, I ‘m great. Except that I’m a fucking eunuch. Scratch the adjective.
I presume the adjective here would be 'f***ing'.
To be a eunuch is to have no testicals, typically a purposely castrated male. It is a play on words - using the sexual meaning of 'f**king' - as to have intercourse and it's other meaning to suggest intensity on the following word.
But a eunuch is 'powerless' and has no sexual urges. SO, depending on the context - it would either mean that if it is about a REAL eunuch - he can't perform a sexual act due to impotence. If describing a situation, that he is great but powerless. eg. A fantastic detective, but he is not allowed at the crime scene.
5. "You’re doing a fine job. You’re helping to protect us against the hordes. "
"Those who try to bring this great country to its knees."
The Hordes simply refers to a large unruly, often evil or demonic 'army'. Think of 'Lord of the rings' or 'Gladiator '- the battle scenes with barbarians - they are "The hordes".