..1) "If I have to eat the leather on the ship's yards, yet will I go on and do my work"-Magellan answered resolutely
Is yet here used to imply that sth could, might, etc. happen in the future, even though it seems unlikely? But I think it won't match the meaning because he answered it resolutely
2) For even if sailors knew the directions of the winds, they could not know whither those winds would carry them, and as there was no inhabited land beyond, they would run the risk of being lost in mist and vapor.
Does whither here mean whether? or whatever place?
Both #1 and #2 are archaic sentences. "yet" = despite everything; "whither" = whatever place.
3)If you will look at the different pictures of George Washington, you will see how he changed in appearance .....
So what do the sentence mean when using to will? If I understand you, it is saying if you will do x, you will see y = if you carry out action a, you will see b.
What do you mean by "to will"?
Student or Learner