Hello Iarant
Yes, maitl, ahuacatl, tetl, they are pronounced like that, but the TL is pronounced as well. Listen to the pronunciation of "ahuacatl" here:
http://es.forvo.com/word/ahuacatl/#nahIt's the first link, by Benjamin.
"cempohualli ihuan chicoeyi tetl" is correct. In nahuatl, objects are seldom pluralized. You usually pluralize people, mainly.
"inic ce calmimilolli" is correct.
Yes, the H is silent in "Nahuatl", "Cihuatl", "Nahui".
Words with a "tzin" ending have the stress in the second to last syllable. "tlac
Atzin" for instance.
Si la vida te da la espalda, agárrale las nalgas.