Since birth my 6 month old doesn't burp much when she is nursed, but she will fart a lot. Does farting get gas and air bubbles out the same way?

No. Much better and more efficient to lose gas bubbles by burping. Lower abdominal gas is also much more uncomfortable.
10. Most nursed babies don't get a lot of extra air because unlike bottles the is no air trapped in the breast. Occasionally a baby will snort air through the nose and sound like a piglet when nursing. Gas can also be passed from below. As long as the baby is not fussy you do not need to worry.
Has to go somewhere. Gas in infants is very common and usually benign. I wouldn't worry as gas usually exits out one end or the other. If it becomes problematic some doctors may suggest mylicon/gasex.