What is the approach to handle failover and compatibility issues when patching FCI nodes?

Question

I have FCI with 2 nodes.

Following is steps to patch the nodes:

1. Remove node from Possible owners
2. Patch the inactive node
3. Add the node to the Possible owners
4. Failover to inactive node
5. Leave it running for 1 week to ensure no patch related issues
6. Remove the other node from the Possible owners
7. Patch the inactive node
8. Add the node to the Possible owners
9. Failover

My questions:

1. Point 2: before this, do I need to change the FailureConditionLevel to 0 so that it doesn't attempt a failover?

2. Point 5: At this point if a failover occurs then it will make sql server go from the patched node to the unmatched node. Will this introduce any compatibility issues since both nodes don't have the same patch?