In the tourney, people were putting Airbases on Germany and North Italy–defensive ones to gain the 6 plane scramble.
The BB only needs to be risked in order to break the odds and gain advantage so that basically, you only have to lose subs and sea hits, not planes during your opener. There is no reason to risk this unit, in general. You are risking it to move your odds from 80% to 90%. Considering how valuable it is in making the rest of your German Navy viable for the rest of the game (even without the added carrier), there is also no really good reason for making it fight alone at any point.
The Scotland attack is pretty good if you can force England into a situation where they cannot attack the Scottish stack AND continue in the defense of London, because there is a follow on force of Germans ready to counterattack. Then, you can attack them from land and sea and that would be it.
The problem there is that you have to leave your German navy in a vulnerable position at least one time, and the UK (playing conservatively with plenty of fighters) should be able to kill it. That means, no second round because the transports are at the bottom of the sea.
My general analysis is that you need at least 2 incremental reasons to rationally build an airbase (though the reasons could derive from the same situation on the same turn). Those reasons could be reduced to a single scramble at some point during the game, one move of extra distance, or one situation where the implied threat deters an attack. Only using it one time for one reason isn’t worth 15 unless it was life or death for your capital or fleet (such as building one on Denmark, korea etc) Most situations you can find a reason to get to use an AB way more than 2+ times, if you can’t, then the carrier is way more flexible its basically a cheap pile of free soaked hits (like transports in the old game).
But the real reason I don’t like any of these plans that YG lays out is the “stranded transport” rule we keep discussing. It is too easy for UK to drop a single destroyer into the channel zone, making it hostile. The best reason to set up the Holland airbase wasn’t to defend the Graf Spee/Bismark it was to make a bridging block with the Germans so that they could hold the channel with a well defended fleet and bridge units directly across the channel without any reply. This isn’t possible under the more correct interpretation of the rules that would force the transports back across SZ 112 to pick up their troops because it requires you to stage the units in Western Germany, not Normandy. If all the units are in WG, then you have to move there to pick them up and there is no channel blocking in this manner. By using blocking destroyers, the UK player could stop you from being able to load your transports in either square. And no matter how you enforce this block or attempt the SZ/defense/takeover, if you cannot do it by UK4, you lost the game.
The hit and run idea is way better for those reasons…