Ship might be along later, but for the moment let me add my thoughts.
The fixtures in question are low
voltage, with a
transformer, correct?
If so, you can blow all your sums out the window. In an ideal world it would be fine, but ideal transformers simply do not exist. You are going to have significant
power losses due to the
transformer. In some instances I think that
transformer can be as little as 50% efficient. So to
power your 30
watt globe, you could be pulling as much as 60 watts of
power. I think that transformers tend to be more efficient than that, but they are certainly no where near 100%.
I recall that in the past there was a discussion over the overrating of fuses. Just because a device has a 1 amp
fuse does not mean that it draws a full amp. Manufacturers seem to like installing fuses of much higher value than they need to. It does mean that there is little chance of the
fuse needing to be replaced but that comes at the price of protection. The higher rated
fuse will not blow until the fault condition is more significant.
As for the
inrush current, all
incandescent loads will have a start up
current, so it would be no different to say 2.4kW of say PAR56s in terms of startup
current I would tend to think. Breakers will normally be able to tolerate this inrush, because it will only be for a short period of time, unlike say a discharge lamp where said inrush lasts several minutes.
Just some food for thought, hope at least some of it made sense.