None of these things requires Trump to be a Russian agent.
Spreading Russian propaganda
Which happens to coincide with what he wants people to believe. He also spread propaganda from British fascists, but it would be risible to suggest he's in their pay.
Blocking measures to protect elections against more Russian interference
In order to deny allegations that Russian interference may have helped him to the presidency. Simple self-interest, no collusion required.
Abandoning Syrian Kurds so fast the barracks were left up for the Russians to use
Withdrawal of US involvement in foreign wars was a Trump policy since before the election.
Delaying Ukraine aid, to harm their defense against Russia and trust in the US
Which we know was done as part of a petty attempt to smear a domestic political opponent.
Extorting South Korea leaving them more open to China
Don't know the details of what's being referred to here, but it does not appear to have anything to do with Russia.
The extreme Russophobia amongst US Democrats does make you look like the reasonable ones in this argument. No collusion with Russia is required to explain anything that Donald is doing, and assuming it without evidence makes you all look paranoid.
Coincidence of interests does not imply collusion. The Soviet Union once really hoped the Campaign for Nuclear Disarmament in the UK would succeed, and went so far as to secretly funnel them money. Despite the allegations of paranoid right-wingers, however, the CND were not colluding with the Russians and were not Russian agents. They wanted disarmament for their own reasons, and the Soviet government happened to see a coincidence of interest.