Well, that was interesting. The loaded trailer had surprisingly little effect on the bike handling, less so I feel than the equivalent weight in panniers. You obviously have to be aware that it's there, so go a bit wide when taking corners, and it can make you wobble a bit at low speeds, like when pushing off, but in general it had little effect. At one point when I was tanking it a bit, a sidewind made things wobble, but otherwise no real stability issues. I was marginally slower than my normal commute, 13.2mph average vs normally between 13.5 and 14.5mph, but that may just have been due to taking additional care when going around obstacles (ie cars, lorries, vans etc)
I'm glad I put the flag on the trailer, since otherwise it's a black trailer with a black bag in it, at about 6" above the ground. More than one car driver who looked like they were waiting for me to clear the junction before the accelerated out actually seemed to pause when they realised that there was something behind me, which I think would have been less obvious without the flag fluttering in the breeze.
The spare sleeping bag, which I just bungeed on top proved to be interesting, since it's quite hard to attach something which is essentially round and slippery in that fashion. I ended up using three bungees and the handles of the Yak Bob Sac to hold it in place!
Sorry to hear that we're already loosing people to the Zombies... (metaphorically speaking anyway). I hope you improve soon Wow, that sort of things isn't exactly fun (not that being ill ever is).