Well, 10 years ago to the week, Mount Stromlo Observatory burnt down. The owners of that also own Siding Spring, and put in place many measures. Like clearing trees, and installing fire mesh on all the windows.
Problem is, the flash point of eucalyptus oil is 47 degrees, so on hot days the country is basically guaranteed to erupt in a massive fireball. Fireballs have been observed rolling along bare earth for a km, just igniting the volatile oils above the ground layer in the air.
Other problem is that we've had record rains for 2/3 years so burnoffs couldn't really be done. And now we're back in a record hot spell, and everything has completely dried out in the past 6 months now that La Nina is back. It went from too wet to burn off to too volatile to burn off in a blink of the eye (and since there are government organisations involved, it could be argued they can't act that quickly :) .
Most buildings on the mountaintop are 1970's era. The main 3.9m dome has no active fire safety equipment in it, but it is clad in fire proof material and was always intended as the fire safety refuge for the entire mountaintop, since there's only a single winding road off the mountaintop (which always scared the hell out of me in Summer).
The lodge on the other hand had wooden doors, was quite up close to the bush (a feature, because it moderated the temperatures for the astronomers sleeping during the daytime), and was sorely lacking in maintenance (although when I worked there, I could hear workman on the roof often enough, so I presume they were clearing leaves and twigs from the roof).
Fortunately, yesterday was Sunday. The photos the guy on duty took just before leaving look awfully scary to me, but he's a firey, and knows what he's doing. Might have been interesting to get all 18 staff and x number of visiting astronomers off the mountain in a hurry if it was a week working day the bus was back in town and not available when the evac was called. Not much room to land a chopper (although it's been done before).
By the way, it was 40 degrees on the mountaintop yesterday according to the onsite met tower (prior to reading 104degC for a couple of minutes as the fire passed over). When I worked there, I found that if it was hot on the mountaintop, it was unbearable in town. The constant temperature inversion meant that it was always 10 or so degrees hotter in town. Yesterday was a frickin dangerous day. I haven't looked, but I suspect we made a lot of use of the new category of fire danger that was introduced after the Victorian Black Friday fires a few years ago - "Catastrophic (Code Red)". That's the new category they now use to say "get the fuck out, don't even try to defend your purpose built property. You will die.".
As to your question about burnoffs; of course burnoffs are regularly done onsite. There's a dedicated fire truck on site, large tanks of water, fire pumps, a trained staff fire team, assistance from the local RFS. Every few years they burn off different sections of the mountain and the surrounding national park. Using a coordinated, evidence based approach (ie, not the method you would use if you typically read The Daily Smellograph and other Is Your News Limited? publications).