How does Lubavitch (philosphy, practice, and followers) differ from mainstream Orthodoxy? What is the basis for the claim that the late Rebbe is/was Mashiach?

In class, when asked what the most important aliah is, i responded with the maftir. However much to my dismay, my teacher said that not only is it the least important, but also that it does not even have to be said by a Bar-Mitzvah, or it can be said by someone who has had an previous aliah. When asked why, the Rabbi said that.. 1.It is a repetition of the torah reading, so we are just saying it again, and therefore does carry the importance as a regular aliah, and can therefore be said by a non-barmitzvah. My question is, if you are on the Trieneal cycle, is the same thing true, because you have not already said this specific passage in the days normal torah reading. So therefore can the person that says the Maftir Alliah, be below the Bar-Mitzvah age, and can it be someone that has said a previous aliah.

when/how do we know that God's answer to our prayer is NO.

my question is my dad past away on January 5th, 2005 & I received a card from the chapel,as a reminder to light a Yortzeit candle . But the date on the Reminder they sent is Monday, January 23, 2006 (24 Tevet). When should we light the yarzeit candle?

My question is what day should you go shul (synagogue) on the day of death or on the day of Monday, January 23, 2006.That was sent to us from the chapel?