Merhabalar arkadaşlar

I have a question about the meaning and usage of the following 

bari, en az, hiç değilse, meğer

and others that I´ve been hearing in the series that seem (at to me) to have the same meaning as at least, apparently. So do they all mean the same and when to use each and how?

Şimdiden teşekküer ederim, hem de çok.

az (1few, 2littler)

daha az (fewer, less)

en az (fewest, least, minimum)

http://www.turkishclass.com/turkish_lesson_287

en az+ı(possessive)-------------------->en azı (purely: its least)

en az+ı(possessive)+dan(ablative)------>en azından (purely: from its least) (normally: at least)

en azından=hiç olmazsa=bari* (at least)

*pronunciation: baari

http://www.turkishclass.com/turkish_lesson_281 (this page includes "meğer") "to my surprise"

Kimse yok mu? 

Kimsen yok mu? (Don´t you have anyone?)

What did you mean?

Kimse yok mu?

İs anyone here?