complexity-theory,time-complexity,asymptotic-complexity,amortized-analysis

Yes, it can. Amortized complexity takes into account the frequency with which the worst case appears. Thus as soon as the worst case appears in about 1 in N^2 operations the amortized complexity will be constant. Let's take a simple example - the dynamically expanding array(I will call that vector...

sorting,data-structures,linked-list,sorted,amortized-analysis

O(1) amortized means that a sequence of n insertions costs O(n) time in the worst case. This is not true for this case because inserting the elements in reverse order takes O(n*n).

java,algorithm,arraylist,time-complexity,amortized-analysis

No. "Amortized O(1) time" means a very specific thing - it means that the cost of inserting n items, one at a time, is O(n). It is not enough to say that "the things that take a long time don't happen very often" - you do actually have to analyze...