Hi @Benyam Ephrem,
I'm a Computer Engineer major from Florida State University. I work as a federal contractor to a company in Virginia currently as a Technical Team Lead/Sr. Software Engineer. To answer your question "should I start investing in the D.C Metro area and follow my plan of getting a rental senior year and then moving out?"
I'd say Do It! Buy a place and rent it out while your in college to live practically for free. You have your parents support. You are very mature, understanding, grateful, understand the situation which you are currently in, see an opportunity and willing to take action.
Here's my reasoning for saying - Do It:
I wish I knew about BP when I was in school. There was an apartment complex that was vacant, until my last year when it was rehabbed and rented out, full vacancy because it was directly across the street from main campus. I wanted to buy it, but hadn't a clue where to start, so I never did anything regrettably. As a CS major you are in HIGH demand, and will be for the next 15 years, what I mean by that is getting a conventional loan will never be an issue. By the time you graduate, you'll have a steady source of income, with tax benefits should you choose to take 6 months off and enjoy life before jumping into the 9-5 realm for the rest of your life.
Plus, as a student you have something most working professionals do not, TIME, use it to your advantage and learn as much as possible, via volunteering to help out an investor with a website or something else that adds value. If done properly you can have enough income to maintain a pretty good lifestyle while you shop for your dream job.
Good Luck.