Looking over the forums here at the STF, my opinion would be to keep the number of forums limited! A balance needs to be struck where you don't have too many nor too less e.g. just one forum for fuel injection is better than individual forums for D-Jet, L-Jet, K-Jet, etc.
Watch the overlap between what you offer vs. STF. If you both have a FI (fuel injection) forum where would one go? For example here at STF, if a newbie with a stock 914 has a FI problem which forum do they hit, the Porsche 914 or Type 4rum or Fuel Injection? With normal shop activites, along with forum responses, it'd be better for you as well as others (like when doing a search) if you could consolidate your responses.
Speaking of searching, spend the extra time/effort/money to get a good, flexible search engine if you really expect people to use it so as to save you time in answering repeat questions. Keeping threads 'on topic' and removing such posts greatly helps to keep the signal-to-noise ratio at an optimum and threads more concise. For example, the gun hobby should be removed and placed into it's own thread.
Just my $0.02 as a long-time forum user. Good luck with your endevor!
