Finally found a little time to work on it more. The baluster railings are on now, everything is lag screwed, and it's all braced up. Even though my wife might want to eventually enclose the bottom we wanted it open for now to walk under. So I did 4x4 Y bracing on the side to side and single 2x6 X bracing on the up & down. It's rock solid stable front to back and pretty close side to side. If I jump around and throw my weight around it will move just slightly side to side, but it's not a problem and I'm not going to do any more bracing.
I'm off work Friday and going to try to finish the roof and work on my dock some more. I was originally going to use some extra 5/4" x 6 decking planks for purlins but have decided to buy a few more 2x4s. The 5/4" stuff might split plus nails would stick out the bottom of it. Here are a few new pics:
