one thing that can help the wheelsets is to put as large tires as you can. This allows you to run lower pressures, and will increase the "suspension effect" that will put a lot less stress into your spokes and rims. I'm a lightweight, so don't have specific suggestions of pressures, but probably in the "clyde" section, you'll find some good suggestions of both tires, widths and pressures.
I do know that even as a light guy, wider tires and lower pressures have made a real difference for my loaded up bikes wheels and spokes over rough roads, in my case 2in tires at pressures that work for me 135lbs and maybe up to 60lbs of stuff (somewhere in the area of 40-45psi, you'd need a fair amount more)
all the best with slowly increasing your riding, and do be careful of locking it up and where you lock it up, they are nice bikes that a good bike thief will notice.