chalet -- es un tipo de casa muy grande, lejos de otras casas. Why here we put "otras" in front of "casas", instead of "casas otras"? I thought the adjectives in Spanish always appear after the nouns.

1.El Senor Perez no tiene el boleto 2.Senor Perez no tiene el boleto is the second wrong? Do we have to add "la" in front of senorita and senora as well?

"Augusto está triste porque se ha separado de su mujer." "Nosotros estamos enfermos." Why we use "está/estamos" instead of "es/somos" in these sentences? Here is another sentence: "Es triste estar siempre enfermo." Why here with "triste" we use es? I assumed that we use "estar" + adverbs and "ser" + adjectives. Is my assumption correct? Why "estar" can still get followed by adjectives like "triste" and "enfermo" for the above two sentences? Thanks in advance!

What does this sentence mean? "He had frequent fallings out with his literary pals as he assumed the role of the master to their apprenticeships." I assume "fallings out" means fight? but I am not sure about the meaning for "he assumed the role of the master to their apprenticeships". Does it mean that he sees himself as the master and his pals as the apprentice? Or he sees himself as the master of the apprentice of his pals? Can anyone help me in simpler English? I'd appreciate it a lot!