Ride the horse you own

Ride the horse you own if it is safe.  If the horse is dangerous you might want to rethink that.
Bucking, rearing are not acceptable behaviours.  Find a trainer that can fix this.  Be sure to tell the trainer all about it.  Remember this is now a learned behaviour.  It will come back.

Other than bucking and rearing most other behaviours can be dealt with fairly easy.

Do you want a more challenging horse?  Do more with your horse.  Learn to jump.  Learn to drive.
A quiet horse is nice to learn on.  Send your horse for training so she has more to offer.  Even if her half pass is not spectacular you will learn to ride it well.  A bigger moving horse is harder to sit.

A balanced, sane horse is rideable.  You can do everything with it.  Your horse will enjoy doing more.

If you horse has issues then learn how to change them.

A horse that is fast can learn to relax and go on a loose rein.
A slow horse can learn to move out better.

It is just a matter of knowing what to do.

Lunging fixing manay errors in the horses training.  a fast hors wil learn to walk, trot, and canter with his head down, and relaxed.

a Slow horse wil learn to move out with purpose.  It can become more athletic with cavalletti and jumping work.

An anxious horse will trust you more with ground work.  This horse is the most difficult horse to ride as something was done to the horse to cause it to have fear.   This horse must be started at the very beginning.  Bringing in.  Being touched, being brushed, lwalked, lunged, and finally ridden.  It will take a long time.  I have 2 horses that had a traumatic start to being ridden.  It has taken 4 years to be able to ride the horse somewhat, the be in the barn without going crazy.  It think it would be easier to get rid of the person that did that to these horses.