Hello Nan
I dont really think using php nuke gives a professional image of your business.
There are a few things I am thinking
Using a free script to power your whole site can give some people the impression that you are either "cheap" or going for a "cheap" market
Although I dont agree with this and Im all for open source, I know a lot of people will get this impression when a business site is using free scripts for everything on their site.
I think thats wrong...but thats just the way some people think
I also dont think using a CMS script doesnt show off your design scripts as much as you should be trying for your own site.
Your own site gives even more of a first impression to people visiting it than any other business site would.
Your site not only shows what your company is like, but its an extension of your portfolio really.
It IS your work
Having a unique design instead of just customising a CMS script would give a far better first impression.
It might be different if you totally change the layout of PHP nuke also, but its still too plain at the minute and there isnt anything to show your skills from someone skinning their gaming portal site.
I think your navigation has to be changed, you have left in a lot of modules which arent needed for a business site, remember that you are using your site to sell your services, not as a community
You shouldnt show stats, have a forum memberlist, PM login, Encyclopedia etc. as they arent needed for your site.
I also wouldnt show the latest posts on your site, you ahve it both under latest additions on the home page, and a scrolling panel in the right nav.
There arent many business sites showing the latest posts for their site on all pages, might help improve it a little anyway
I think you have focused too much on the community aspect of your site when its more business oriented.