To answer your first question - Biden didn't give Putin his oil pipeline - It was already nearing completion when he lifted US sanctions, as the US
sanctions only slowed the construction of the pipeline and the US didn't have the ability to stop it from its completion. It wasn't a gift but it was a
sign that the US had enough of it. Though he said he would do everything he could to stop the pipeline, it was well on its way to completion.
Biden didn't refuse to help Ukraine prior to the invasion. Policy in place was from decades of poor policy planning by W, Obama, Trump (if any
policy he knew about - more likely he did everything he could to weaken US ties there.) which were continued in the early part of Biden
administration. Your take on it is off the mark and only a Trumpian MAGA hat wearer would conclude that.