Please forgive me if you can't undestand what I'm saying but I'm not native english speaker. If you have any question don't hesitate to ask.
This is not the whole list of things to keep in mind when modeling your own characters in a blender, but enough at the beginning. I am writing this post after to save time for beginners like me. I learned a little bit so will share my knowledge.
Above all, remember the make perfect wieght paint. If any vertex is not assigned to the bone the whole mesh will be spoiled.
Remember that the center of your mesh must be at the center of world grid of Blender(SHIFT + C to stick the cursor 3d at point 0,0,0). Otherwise, the shadow of the object will be next to it. The object itself will move strangely.
Be careful with angles greater than 180 degrees. Try to avoid such transformations.
Try to place the textures in the same folder as your model.
It's enough to do an animated model and export it to the FPSC.
I recommend using Kira's exporter you can easily find it here.
http://forum.thegamecreators.com/?m=forum_view&t=166987&b=3
Hope that helps.
And here is what I've managed to do using the above rules. It works in FPSC.
Blender animation - render
http://www.youtube.com/watch?v=xJC5jUhwXJg
FPSC character test:
http://www.youtube.com/watch?v=B54mEN0E3VI
