This tall Rivieria Rainbow is bent at the top. It is about 8 feet or taller and all stem except for the bushy top. Should I try to straighten it out? How? Or should I just wait til spring and cut it back? Where? (scared!!)

While Riviera Rainbow is a tall grower yours seems unusually lanky. Is it getting full sun?
I would wait to do anything until spring, personally.

I saved one Riviera Rainbow from last year's bad winter. I will take a picture later and y'all can critique it for me.

Hetty, the tree came to me 24" tall with three branches. 2 branches snapped off spring 2013. I was heartbroken but I was able to start those cuttings. I gifted one cutting. The cutting I have is now 3 feet tall. The single branch on the mama tree continued to grow to the 8 feet it is. I think even if I straighten the bend in it, it will continually want to lean because it is so lush at the top. I will wait til Spring, but yes, I think a sever trim is necessary. At what height should this be done?? Should I trim the upper part then as well. Each branch is about 18" long. It gets as much as my driveway sun can get, about 6-7 hours a day. It just is just top heavy with those large leaves.

Cheryl, this is my Riviera Rainbow. I already took a sizable cutting from it a couple of weeks ago (you'll see that "stub" on the lower left side) and the other branch has three long tips. You will see the cutting end I took last summer where this new three-tip branching occurred. I hope that branch that was cut two weeks ago will begin to grow new tips before dormancy halts all growth.

I won't cut that three-branch until next spring. I might cut it intact, or I might take three cuttings. It just depends on how long and mature the three branches are at cutting-time.

Here is a picture of the Momma tree of Riviera Rainbow.

That's a whopper of a tree, Hetty! My plumeria can never be trees.