Banner ad on left sidebar is too long, it doesn't make any impression for the first visiting.
According to my personal opinion, logo it not good widh 3d effect, make a flat logo, may be better.
If you are going to build a large community, don't go with phpbb cms, it's free and will not have more functions/mods/addons for you to manage it when your forum has more members, posts and even spams
Try vB or Xen, they are good choices to start a forum.
Mzansi? Now I have to check that out. Take the advise WMS just gave you above, the only problem I see is that your forum is not focused it covers a lot of different topics that are not related.
Maybe it's a good thing to be general but I would keep it niched to a specific audience. This will make it hard to get good advertisers because advertisers want a specific niche audience.
I also clicked on your social media buttons and realized that facebook button doesn't open in a new tab. I would also advise you never use a free script, upgrade to vB or Xen for more flexibility and to avoid spam and bots messing up your forum.
Your logo doesn't bother me. I think it is ok. I agree that you must think long term and start off with a better forum software. I also think ad is too long on left. It is easy fix. Just delete one ad. The current board loads fast for me.
I think your site load fast...template and color so classic but still elegant, because you placed banner ads in left side is good idea. I think your logo doesn't impress me..it just so. I guess you should change your logo that can make other people impressed and easy to remember but still have good meaning and philosopy. Good luck for your web forum.