The "strut" that is closest to your tire replaces the UCA. It keeps the tire/wheel located and moving in a straight line verticaly. Without it your wheel would lean in and out. On a stock truck your UCA does this (and looks just like your lower control arm). The UCA was remover and replaced by the "strut". The stock UCA was not reused because it would have been at full droop and binding. Some lifts get around this problem by usinbg an upper ball joint spacer. This allows the UCA to be at the same angle as the LCA. (this is a good thing, this allows the wheel to travel up and down in a straight path) The LCA is lowered by the bracket lift, allowing it to be ~ factory angle.

 

I have the same lift on the 96' tacoma i just bought and where the "secondary strut" mounts at the the top the bushing is practically gone. Would i be able to remover that strut and replace it with an upper a arm? and with that bushing being so worn out the top of the strut is falling inward causing the tire to camber

 

If you get rid of the lift and all the stock suspension mounting locations are still there, then yes you can put the upper arm back on.