I read it as these spells are totally optional - they're added to the list of spells that you can choose to have as 'spells known', but must still be chosen as normal (at your discretion).
I do think that beating a war drum that tames the wind spirits would be culturally acceptable though (vs say, summoning a celestial meat shield or casting burning hands).
There will be a number of sea voyages, so Sea Legs will not be wasted.
Yep, also a solid & fun choice...