The Treaty on the Final Settlement with Respect to Germany restored the country's full sovereignty. The positions it reaffirms don't limit what Germany is allowed to do under other treaties. It doesn't prevent Germany withdrawing from the NPT. It doesn't prevent Germany from doing anything that other sovereign states can do.

Germany bought a small number (35) US fighter jets as replacement for the aging Panavia Tornado used as bombers carrying US nuclear weapons as they are not allowed by their allies to have their own.

This is a very weird claim. If Germany wanted to build its own nuclear bombs, it could withdraw from the Treaty on the Non-Proliferation of Nuclear Weapons. Germany could also have asked to host French nuclear missiles instead of US nuclear bombs, possibly as part of an EU-wide agreement rather than a bilateral deal.

It's a subsidy when the state ends up paying the difference between the guaranteed price and the average market price.

Rappel : le président du Sénat suppléante le président de la République. Si Macron ne peut plus remplir ses fonctions, c'est Larcher qui est temporairement au pouvoir (article 7 de la Constitution de 1958).

I guess another way would be fixed prices for all nuclear and renewables since they have fixed costs anyway. The thing is, the system already works that way to an extent, as there are a lot of guaranteed prices in renewables and some in nuclear. As far as I can tell, these subsidies are why the market price sometimes goes negative when solar or wind produce a lot: the subsidized sellers don't care, they still receive their guaranteed income based on the quantity of energy they inject into the grid. It seems to me that without these subsidies the market prices would always be high, thus better reflecting the true cost of electricity.

Setting the electricity market price based on the most expensive source at any given time is pretty much universal in Europe. It's an EU thing, not a specificity of the UK.

Changing this rule would reduce the income and profits of climate friendly electricity providers, thus penalizing the investors who tried to do the right thing.