Not really, but there is critical support, which is how Marxists see this situation.
Critical support is supporting something while also being critical of its flaws. It is often used in the context of supporting bourgeois states that fight against imperialism or are under imperialist aggression.
Is there an option to not support anyone?
No you either support imperialist invasions or you don’t. There is no fence to sit on.
Not really, but there is critical support, which is how Marxists see this situation.
Nope. Think of it like a trolley problem.