Ridge pole vs Legs
Hi. You may enjoy scanning the Turtlelady Bamboo Stand thread.
There I and others have detailed several experiments with the materials you are suggesting, ie, aluminum and conduit used for legs and for ridgepoles. Some experiments were fairly dramatic let downs!
My advice after much experimentation:
The ridge pole must withstand considerable compressive forces. I have not found lighter weight poles that have not let me down in this application. For the cost, ready availability, ease of cutting to size, available cheap connectors that work well in short segments the steel chain link fence top rails are hard to beat FOR THE RIDGEPOLE. One of my often used stands has the 10' ridgepole cut into 4 sections. Another has it cut into three segments. Most use the simpler 5' segments, when compactness is not an issue.
The LEGS can be more lightweight and use more variety of materials with some success if you are gentle with them. Your weight divided by six plus some dynamic load are the weight they must hold, which is much less than the compressive forces the ridge pole endures. I have successfully slept many nights using segmented aluminum tent poles for legs which were lashed together. See photos in that thread.
I recently acquired the canopy support system discussed in Turtledog thread #203. The 4' swagged segments of aluminum poles are stunningly wonderful in sturdiness and ease of use for the price. But the segments are heavy. They are appropriate for both Turtledog and Turtlelady stands. And for holding up booth signage very high in the air in my traveling festival face painting business! I love them.
For the record, the company near Harrisburg PA that sells those canopy support systems will sell the poles by the single segments.