Would it be possible, from the earth’s creation or during its various geomorphological changes, for all the following hypotheses to be probable?
The second part of the question is easy to answer - given that the Arctic has been ice free in relatively recent geological history, e.g. in the Mesozoic, and it is expected to be ice free in summer within a few decades as a result of global warming, positing a habitable planet where polar oceans are navigable, at least in summer seems fairly safe.