Yes, it was quite an adventurous trip, and one I will never forget. Most of the way, I did by pedal bike on the actual railroad right-of-way, biking on the well trod path alongside the tracks. I walked my bike across bridges and through tunnels using a headlamp. For some segments, I also used paralleling roads although these were pretty limited in southern China. Housing was more of a problem, I would pay for a bed, room, or space to sleep from the local farmers; such types of home stays for travelers were no problem. I might add that this was all facilitated by speaking Mandarin Chinese.
The bridge that you show, RenziQiao, I walk up to and across but that part of the line was dormant at the time. I’ve heard there might be trains on that section of line again now.