First of all good work sticking to your plan and starting something online. Mine is just to offer my own experience
1. It is a good idea not to antagonise possible users to your website. One or two bad clients are ok but not a whole group of possible users. So avoid using terms like I don't give a damn.
2. I am still trying to figure out what your niche is in your site. As far as I can see,you are no different from Haiya,facebook,or that zuqka thing. I think I have seen more like funkenya and other's whose names I cannot remember. So the question everyone is asking you here is,why should I join your site and not Haiya? No technical terms please
3. Alexa is not and will never be a judge of success online. I can give you alexa rankings of less than 100,000 in a month if you pay me $100. It is gamed all the time. For example,if my site does not have that alexa thing they like giving people,then I will never rank. My advice is stop wasting time searching for alexa rankings. Only newbie webmasters even bother with that site.
4. I would be more concerned with SERP's. I can't find you when i search for Kenya social network. Does it matter? More than you think. If you ever wish to sell your site later,no one will ask you for alexa but your SERP's. You should work on your SERP's starting now. You may say you are not going to sell but if I start a social network now and concentrate on SERP's,I will get more members than you.
5. As for your domain name. It is all in the eye of the beholder. So far,I have mistyped your website 4 times. mixbook,mixxbox,mixboks,misbooks. I guess you get what I mean. it is too late for that now so do the best you can with what you have. Even yahoo is a name I can't type right.
6. The colours of your site mean didly in the bottom line. As long as you have good content,I will come back. Otherwise,I would never come back to sk. I can show you a simple blogger site that is bloody ugly and still makes more money than a matatu in Kenya. Concentrate on content.
7. You can use Obama pics if you got them under gnu/gpl licence. they would never bother with your site since its not registering anywhere on the net. But for your own good,you don't even need to use them. You don't see facebook with Ronald Regan pics do you?
5. Now go and market your site and don't bother with one or two members. Social networks have a life of their own,you should be more concerned with online marketing of your idea.
I still don't know the idea behind mixxboxx but all I can do is wish you luck. Please do not underestimate the amount of work you have set up for yourself. I would be less concerned with what guys think in SK and spend my time on the site. If you need help in SERP's domination,you can get in touch.
Jose: If I make it through this thug life, I'll see you one day. The Lord is the only way to stop the hurt.