Limit the times the public can visit I'm sure they enjoy looking at it and it would not go over well if you didn't let them at all . Build a modern living quaters inside and a prep storage with solar power with a water pump and gravity fed from the water suply you mentioned . Is it just me or did they build the roof to look like a Swiss 1918 Militaty helmet .
I can't answer that poll with the options provided. The need(Or want) to bug in or out for me depends on what the situation is. I mean, what if there is a natural disaster in the area? What if there is civil unrest and raiders are likely to surround the joint?
I can clearly see the reasons for bugging in and holding down the fort, but I can also see reason in thinking that one may need to get out. Even if your location is a castle(Which is ridiculously awesome by the way!) I just read you other post about how this castle came into your possession... This spot is awesome, but I would imagine that it's worth more in $ than it is a a prepper bunker. What about selling it and making your very own MODERN prepper spot? You could pick the land, the location for hte building(s), whether they'd be above ground or not, what the security plan is... etc. EVERYTHING. I would imagine this castle is worth a bit of coin. It may be too sentimental, but it's something to consider.