Is my DOM too thick?

[Mike Bradbury]

I am in process of converting a C20 to C10 and getting rid of the rear leaf springs. I am building my own set of trailing arms too. Never could find a thickness from any of these companies that sell trailing arm kits, they only described them as heavy wall DOM tubing. So I bought some 2" x .250 wall DOM tubing notched and welded bushing ends, and got some soft polyurethane bushings.
Now I am starting to think that the tubing might be over kill and will not flex enough, and cause the bushing and weld to take the brunt of the torsion. I know that that is the bushings job but the original trailing arm was able to twist more, relieving the crush factor on the bushing. Also since I went with poly bushings they are a bit stiffer than the rubber so this in turn is going to add quite a bit of torsion to the weld. I am confident in my welding ability, but the more I think about it I don't want to add repetitive strain day in and day out, plus I don't want to have to replace worn out bushings every 20,000 mi. Where if I went to a thinner DOM that has a little flex in it might solve some problems in the future. I would appreciate some advice, am I thinking about it too much or is it just too stiff.
Sorry the images kind of suck, only had a cell phone on hand.