>Anyhow, how can capitalism and socialism coexists? Well, it already does!
No (well, "no" from the point of view of scholars of socialism, whose opinion as experts on the topic matters more). Taxes are not "socialist", because "socialism" does not mean a safety net within capitalism. Means of production, as they are spoken of by philosophers, cannot be said to be "jointly owned"[0].
>Sweden the state spends around 50% of GDP so it already owns 50% of everything even if the papers says otherwise, you can't come and say that something which can extract 50% of all value from something doesn't really own it!
These do not count as productive capacity, but as help for workers, even if they were monetary equivalents (quantitatively), they are not qualitatively the same thing. In fact, one of the problems in the theory of exploitation is the question of whether someone who earns a very high income can be said to be "exploited". The compensation, it is held, is not (or less) relevant than the share of productive resources.
>For example, most roads are socialist, you don't have to pay to drive on them even though they cost a lot of money.
Socialism isn't about "fairness" or getting something back from the state[1]. Rather, it's about "class society". I don't mean to argue for or against socialism, but it's important to get the views right. Social safety nets are a social democratic measure within capitalist society. They are "social" but not socialist. Taxes existed in Marx's time (in some cases, higher than what we have now) - nevertheless, Marx called for the establishment of "socialism". Simple redistribution is not the socialist paradigm, except in rare incarnations.
[0] One of the conditions outlined by Roemer, as quoted in SEP: "If S were to withdraw from the society, endowed with its per capita share of society’s alienable property (that is, produced and nonproduced goods), and with its own labor and skills, then S would be better off (in terms of income and leisure) than it is at the present allocation."
[1] "What is "a fair distribution"?
Do not the bourgeois assert that the present-day distribution is "fair"? And is it not, in fact, the only "fair" distribution on the basis of the present-day mode of production? Are economic relations regulated by legal conceptions, or do not, on the contrary, legal relations arise out of economic ones? Have not also the socialist sectarians the most varied notions about "fair" distribution?" (Marx, Critique of the Gotha Program, 1875)