The way I see it, you have 4 options;
1. Stop riding
2. Continue to ride, getting better with practice, assuming focus on your problem areas. You will learn nothing travelling in a straight line. Practice starts and stops, using cones and an empty parking lot if necessary.
3. Lower the suspension, and thus the seat. See reasons below.
4. Get a SIGNIFICANTLY lighter bike with a manageable seat height (32" or less), which will allow you to manage poor stopping skills until you gain more experience. The Versys weighs 454 lbs wet and has a 33.1" seat height. There are not many desirable bikes in the market however. There are 250cc options, like the Ninja 250 (375lbs wet with a 30.7" seat), or the Kawi KLX250SF Moto (302lbs wet with a 33.9" but narrow seat), but you make serious sacrifices in performance and practicality/comfort.
The Ninja 650R is a nice bike, and has a lower seat (31.1") in stock configuration, but it weighs almost the same as the Versys at 441lbs wet, and it will do nothing to boost your confidence, especially after you drop it and break all that new plastic that the Versys lacks.
The real issue is managing 450 pounds of bike with limited experience or muscle strength. This weight is hard to manage at low/stopped speeds, and once the bike starts to get away from you at a stop, it is very difficult to save the situation. Every degree of angle becomes more difficult to manage. Coming to a stop at anything less than perfectly level and upright will be something to work on. Also, you should focus on applying even pressure on both sides of the handlebar when stopping; this will have a more than likely positive effect for you.
Get the lowering kit. Even though your inseam length is long enough, the lowering kit will allow you to spread your feet a little further apart to create additional support leverage.
Adjust the rear shock preload near the lower settings to reduce ride height for the same reason mentioned above.
A different handlebar is not necessary, as the stock unit provides plenty of height and leverage.
I am basing the above comments on actual experience. The Versys is my wife's. It is her second bike. The first was a 1994 Suzuki GS500E, which was lighter and had a lower seat height. She learned a lot on that bike.
When we were considering the Versys, we knew the seat height of 33.1 inches was going to be too tall, especially considering how top heavy the Versys is. Speedy's kit brought the seat height down, as did lowering the triple clamps relative to the fork tubes. We also reduced rear shock preload to lower seat height. She is 5'9" with a 32" inseam. She can now confidently flat-foot with her feet spread out.
She has dropped the bike twice when stopping/stopped, but she proudly refuses to give up or get a different bike. The crash bars were a good investment. Other than needing to continue practicing low speed/starts/stops, she is an excellent rider and continues to get better. More importantly, she has always possessed good defensive riding awareness and judgement, and she always wears full protective gear.
If we were to do it over again, I would have gotten her an intermediate bike, like the KLX250SF mentioned above. The seat height is high at 33.9", but it feels like 32" with the narrow seat it possesses. At 300lbs, it feels like nothing, and I'm sure it would be a non-issue to manage that weight at a stop or low speeds.
However, doing that now would only be moving backwards for her, so we will keep the Versys as long as she wants to keep trying to improve. I have full confidence that she will do exactly that.
Jen and her Versys, shortly after purchase in August 2009. Only mods at that point were the lowering kit and modified/shortened kickstand.