Yi Peng 3 crossed both cables C-Lion 1 and BSC at times matching when they broke

These things happen sometimes, ship anchors sometimes damage cables, but not this often and without serious problems in the ship. Russians are attempting plausible deniability.

If the EU decides to join the US the war is over and Russia will keep the occupied lands. If the EU decides to support Ukraine then because of the devastating sanctions there is a strong chance Russia loses.

So it's in Russia's interest to make life as difficult as possible for Europe over the coming months in order to convince them that ending the war is in their best interest.

Wrong. Using long range missiles is not an escalation. Russia has been using them against Ukrainian lands for years now. Why shouldn't Ukraine be allowed to use them against Russian land?

Russia are at war with Ukraine, so they are bombing them. Ukraine have every right to reply with their own long range weapons too, and that would indeed not be an escalation in the fighting itself.

But, the west clearly prohibited the use of their donated long range weapons in direct attacks on Russia, in order to limit their liability, responsibility, 'participation' or whatever, until now.

Russia have been very clear that such permission would constitute an escalation OF WESTERN 'PARTICIPATION' in the war, and even be tantamount to a direct NATO attack, and so it is at least an escalation.

Whether it is right or wrong is not the point, it is a clear change in the depth of western involvement.

This seems like an arbitrary line [0] drawn exactly where it suits your argument. How does having North Korean soldiers fighting for Russia stay on the right side of that line? What about any components that originated outside of Russia but are employed in Russian weaponry or equipment (for example chips)? The information war is a part of "the war", is an "official" non-Russian hacker or troll crossing the line? Or a non-Russian boat or crew employed for acts of sabotage.

[0] It can be fair to draw an arbitrary line, at least you know it's straight and will intersect whatever is unfortunate to be in its way regardless of the side you prefer. But you're trying to draw tiny arbitrary circles around whatever you don't like and that's feeble.