Moving/Living in Dar

I have been a lurker on the forum for a couple months and I am finally considering a move to Dar es Salaam and I would like your advice.

About me: 25 year old male, single, sales/marketing professional, Clevelander!, experienced traveler (lived abroad in China and Australia), and looking to make a career in an emerging market.

I have done my homework on living in TZ and I traveled there before when I was younger. Questions and concerns I currently have are:

1. I will be going over there on a tourist visa and connecting with an older friend who manages mining operations for a multinational company. He can get me interviews within that industry but I don't know how likely it is for a company to sponsor younger people for work visas. Do you see young/western professionals in TZ often? Because I am young I was thinking about doing an unpaid trial period (1 month?) at a prospective job while on my tourist visa, just to show my ambition, determination, and skill set. Will this be sufficient enough to prove that I deserve a work visa from a company?

2. Living in Dar looks great from what I've read here and elsewhere. Although there is no way I can afford $2k/month for an apartment in one of the expat friendly areas ($500-750 for a 1BR is my limit). I am ok with a shared or mediocre living arrangement as I have lived in sub-par conditions before. What is your opinion about living outside of one of the main expat neighborhoods?

3. It doesn't look like there is a huge singles scene in Dar. I am ok with this as I am not looking for that at this point in my life. However, I still need younger people to socialize with. Is there enough backpackers coming through the city that I could meet up and make some temporary friends at least? Befriending locals is easy I imagine, everyone in TZ was very friendly from what I remember.

4. Business opportunities in Dar... Is this a good place to start an international business career. I know it has it's problems but from the outside it looks like an innovative and forward looking African city with a lot going on business wise. I want to get my foot in the door with a job and hopefully move towards entrepreneurial ventures within 5-10 years.

Long post I apologize, please answer anything you would like, I am open to any and all feedback. If you have any job leads or know people on the ground please contact me privately as I would be most grateful for any assistance in that regard. Thanks everyone!