1 frame connector?

I am going to be putting in the right side floorpan in soon and have a small issue.
I want to put in a subframe connector and maybe my own torquebox before the pan so I have access to reapply the burnt off rustproofing. But, my left framerail is bad and needs a full replacement and I don't know when I will be able to do it. So, my question is can I just put 1 frame connector for now? I won't be driving it until I can at least get the whole back end redone as I want to do that and my drip rails before the front end.
 
Oh yea, I forgot to ask.
I read a thread on here and there was a little debate on if the connectors should be installed with the suspension loaded or unloaded. I always heard unloaded, but now I'm not sure. Same question for the torque box too.