Well spotted bookworm! I did indeed quote from a FAR. As you correctly point out, "Minimum Safe Altitude" is not defined in the UK for VFR flight, and is open to interpretation. In these cases I find it useful to see how others do it, and hopefully the interpretation I posted is something like what Student~C150~Ipswich is looking for to answer his question - which was what is 'Minimum Safe Altitude'
Rule 29 which you cited is not really open to intepretation, it clearly doesn't apply to VFR flight. In my opinion it is there purely there to guarantee some degree of obstacle clearence when you are in the clouds. When VFR cross country your obstacle clearance is assured by visual means. Sometimes I have been VFR 100ft AGL in designated mountainous areas (real ones) and felt very 'safe'. Other times I've been 5000ft AGL and having to constantly search for places to land, and these have been few and far between.
Talking of learning from others. The UK has a 'glide clear' regulation which doesn't exist in the FAA rulebook. It would be churlish of me to say 'this UK rule doesn't apply to me' when I am flying above US cities. Knowing the 'UK situation' makes me a safer pilot, I believe.