With your arm I suggest using wider handlebars with all the controls on the right.
You can get brake levers that work both brakes at the same time (you have probably already done this). The wider bars will provide more control at low speeds.
With the limp in your left leg I assume it is shorter than your right?? If that is the case then set the boom
for your left leg.
You could get shorter cranks like 155mm and lower gearing to make riding even smoother.
My right leg is 32mm shorter than my left (motorbike accident) and I also have limited right knee bend.
I have shorten my cranks to 125mm and reduced the size of the chainrings by the same percentage.
This setup works really well for me.
Cheers
How about that!
A fellow gimp!
On a Cruzbike, as well.
In my case, a car crushed my right leg into the motorcycle I was riding and,
after all the recovery, healing and physical therapy were over, my right
leg ended up a half inch shorter and the knee lost some range of motion.
So, we have similar leg injuries.
Shorter crank arms don't solve for my shortened leg.
A shortened crank will just change the angles and make the pedaling circle smaller.
Here's my short leg problem:
My right foot/right leg X-seam is shorter than my left foot/left leg X-seam.
My knee can handle pedaling big circles, small circles: Pedaling is no problem for my knee.
-Your knee may well be different.-
Here's my short leg solution:
So, to accommodate the different measurements, I added a 'lift' or a shim to the right
pedal.
The shim makes up the difference between my shortened leg and my original-length leg.
Both legs pedal the same circle, balance is restored and all is well in my biking universe.
The shim is a piece of spruce that I whittled to fit the pedal.
The shim is longer and a bit wider than the pedal, for longitudinal stability -this is important.
I lashed the shim in place, because my kayak frames were lashed together.
Lashings are incredibly strong, stable and light-weight: my kayaks never let me down...
and neither has my pedal.
For my long left leg, I lashed a thin red oak shim to the pedal, so that both pedals
would have the same feel underfoot.
The wood is sealed with coat of epoxy resin or two.
First image is the underside of the 1/2" spruce board that shims my short right leg;
the blurry last image shows my aluminum flashing & aluminum flat stock/epoxy resin/red oak composite platform lashed to the left pedal.
Hope this gives you some ideas, some inspiration.
-Steve