[Goose]

I recognize that Sweden would like to have a pledge from NATO to aid its defense if Russia were to attack.  But let's assume Finland is admitted to NATO.  In that world: 

--Is there a remotely plausible scenario in which Russia attacks Sweden without attacking any NATO member?

Sweden absolutely thinks there is. Russia has for years "messed around" in Swedish territorial waters in ways indicating hostile intent. This occurred both before and after the fall of the Soviet Union. Sweden has always engaged in a "balancing act" between to what extent NATO membership would get them dragged into a war that they otherwise would not be vs how probable it is that Russia might try to overrun their country or at least destabilize it.

--Would NATO be deprived of defensive fortifications that it otherwise would be able to erect with Sweden admitted?

Fortifications, probably not. Joint bases, probably so. I share you belief this isn't a "big deal", but there are lots of political issues in Sweden that NATO membership would avoid. In particular, the US would be able to openly maintain some permanent detachments in Sweden that they cannot under the present conditions. There are also quite a few NATO documents that can't be shown to Sweden until they are members. The most important factors are probably psychological for both Sweden and for NATO.  

My guess is that NATO will obtain most of the value of Nordic accession from Finland joining (assuming that moves forward).

Sweden brings much more to the table militarily than Finland. Sweden has a significant defense industry that Finland does not. They manufacture fighter aircraft and quite a few missiles. Sweden is also twice the population of Finland. The Swedish navy is much superior, featuring both submarines and the Visby class GMCs. Of the two, Sweden is a much "better deal" than Finland in that it is better poised to defend itself without bringing along a very long land border with Russia. Obviously, NATO wants both.

[Goose]

I recognize that Sweden would like to have a pledge from NATO to aid its defense if Russia were to attack.  But let's assume Finland is admitted to NATO.  In that world: 

--Is there a remotely plausible scenario in which Russia attacks Sweden without attacking any NATO member?

Sweden absolutely thinks there is. Russia has for years "messed around" in Swedish territorial waters in ways indicating hostile intent. This occurred both before and after the fall of the Soviet Union. Sweden has always engaged in a "balancing act" between to what extent NATO membership would get them dragged into a war that they otherwise would not be vs how probable it is that Russia might try to overrun their country or at least destabilize it.

--Would NATO be deprived of defensive fortifications that it otherwise would be able to erect with Sweden admitted?

Fortifications, probably not. Joint bases, probably so. I share you belief this isn't a "big deal", but there are lots of political issues in Sweden that NATO membership would avoid. In particular, the US would be able to openly maintain some permanent detachments in Sweden that they cannot under the present conditions. There are also quite a few NATO documents that can't be shown to Sweden until they are members. The most important factors are probably psychological for both Sweden and for NATO.  

My guess is that NATO will obtain most of the value of Nordic accession from Finland joining (assuming that moves forward).

Sweden brings much more to the table militarily than Finland. Sweden has a significant defense industry that Finland does not. They manufacture fighter aircraft and quite a few missiles. Sweden is also twice the population of Finland. The Swedish navy is much superior, featuring both submarines and the Visby class GMCs. Of the two, Sweden is a much "better deal" than Finland in that it is better poised to defend itself without bringing along a very long land border with Russia. Obviously, NATO wants both.