Ukraine can't survive without US assistance.

The very first requirement to join the EU is to be in Europe. Try seizing American assets and see what happens.

Your proposal seems fair to me.

If Trump is indeed a Russian agent, why not make him use the soft power to actually help shift the narrative in favor of Russia?

That’s not quite accurate. The U.S. is the country that has provided the largest support to Ukraine. Congress has voted $175 billion for Ukraine. About half of that was sent to them and the other half was spent domestically to help them.

Ditching the sanctions is likely considering they harmed the hegemony of the USD.

It’s going to be hard finding an opponent playing a positive-sum-game

Ukraine is already struggling immensely with the US support. Imagine what will happen without US support.