I think you got some good advice. On my tours I use a light lock. In the city, we (tour with my wife) are concerned about our bikes/stuff and try to watch the bikes. In campsites, a light lock has been enough for the 20 years of touring. Having said this, we have yet to have a problem with bike or stuff.
Do not underestimate weight. Your weight alone will be a challenge. I recently lost 15 pounds to get back to my height/weight recommendation. It has made a big difference in my riding ability. I was surprised by the difference. Challenge your assumptions about what you need to carry. I try to make as many compromises as possible.