If you send send a transaction request to a node, what is to to ensure that node doesn’t simply log your private key and do nothing?
What is to stop the entry node from taking a transaction intended to transfer 1 bitcoin, and transfer 100 instead? Or to stop the node from changing the receiver of the transaction to someone else?
Lastly, what is to stop a node from sending a completely made up blockchain?
Do you just have to choose a trustworthy node?