That is not a completely reliable measure of abundance when it comes to human purposes, after all it needs to be economical to extract these resources.

After all metals like lithium and most of the rest of the "alkali metals" and "rare earth metals" are relatively common, this issue is natural processes do not collect and concentrate them, as they are much more reactive and easily dispersed, so significant commercial deposits are rare compared to its crust concentration percentages.

Gold is a metal that naturally concentrates into deposits after aeons of time, as it is heavy and relatively non reactive, so there are many more commercially viable deposits than other metals with significantly higher abundance.

Indeed. The chemical properties of the elements will make some easier to extract than others. Metals that have been known since prehistoric times (copper, tin, lead, silver, zink and others) easily combine with sulphur in the crust, and can be found as easily extractable ores, while the rare earths are as abundant as these, but do not concentrate much in specific ores. The same goes for Uranium, that is surprisingly common in most minerals.

What matters is how easily the elements can be extracted and processed. Aluminium is 13% of the crust by weight, but was not possible to process before after around 1880, because electrolysis and large scale electricity production had to be in place first.