I'm not sure how long you've lived here, but I can't endorse this advice.
1. By all means take certain things personally, and file them away. Don't make a habit of being shit upon.
2. If someone reneges on a promise, hold it against them forever.
3. If you agree to work for peanuts or for free, you'd better be a college student looking for an internship. Otherwise, you're a jackass. There are a ton of jobs out there, and the market isn't actually all that competitive as long as you show up and speak English. Get paid what you're worth.
4. People "back home" shouldn't think this is insane. They aren't a collection of rubes and hayseeds, they understand DC is the seat of our federal government and you should be able to explain your job to them.
5. Network only if you have to and if you enjoy it. Don't feel like you have to talk shop at a bar. It can be annoying. It's fulfilling to date and have friends outside your sphere of work.
6/7/8. Some people b.s. more than others. You'll figure it out soon enough.
9. Avoid self-important assholes with something to prove. They are poseurs and they can't help you.
10. Tip according to service, whether you suspect your waiter/bartender may someday be in a position to help you or not. Hardworking garden-variety restaurant staff deserve tips just as much as douchebag hill staffers.
I still disagree with the part about the service. I wasn't saying you should tip in the hopes that your server will eventually do something for you. I was trying to, in a midwestern way, talk around the fact that the overstressed self-important people splitting an appetizer over their happy hour special drink for two hours at a table while sucking down eight glasses of water and loudly talking about what a dump the place is might not want to further enrage a service employee who could be encountered in a totally different role sooner than you'd think.