Is the €30 usage fee going directly to the producer of electricity, or is part of it a variable transmission fee that goes to the network operator?

My monthly electricity bill in Sweden, averaged over a year to 1600KWh/month, is approximately €90 production, €50 transmission fee, €25 fixed connection-size fee (25A, 400V), €70 national electricity tax and €50 VAT for a total of €285/month.

We'll be moved to yearly-peak-based transmission tariff in 2027 (European law), but for now I don't need to worry about plugging in the car to chargeon cold days or taking shower when someone is cooking.

Both, currently; notably it's mostly not what goes to your local grid, but rather mostly to the larger scale grid. It's about a 60/40 to 70/30 split between production/"grid-usage-fee" ("Netznutzungsentgelt").

It basically pays off the grid stability provision bids for fast-response power, and the transmission itself.

It'd likely be helpful if the peak part could be regulated in a way that's more condusive to match the actual impact you create on transformer sizing, not the worst-case impact you might have. Because there's a difference between a mostly-uncorrelated peak of shower+cooking vs. the car+cold day, because your neighbours don't shower the same time, but the several hours of charging do often overlap and the cold is the same across a neighbourhood that shares a local substation.

But yeah, for the most part, transformer size isn't that large of a contributor to overall electricity provision expenses, so I don't expect that to be a significant problem by that 2027 law.