recruitment q's - gpa, networking, delaying grad, etc.

I heard some mixed things about GPA on resume, some say leave it off if its under 3.5 but some say if you leave it off people will assume the worst. I have a 3.4 and i'm not sure if i should leave it on or off. 

networking - idk if im networking right. i email alum and non alum at firms im interested in, sometimes they respond and we chat. i learn quite a bit about the firm and what they do on a daily basis so definitely things i can say in an interview, if i get an interview... how exactly does "networking" work? 

i just finished my sophomore year so im a rising junior. heard from some ppl in my grade that they plan to delay grad to recruit again as a sophomore and i have considered this since I have the next semester to bring my gpa up before recruiting again. should i continue to recruit now with a 3.4 or delay grad and recruit again as a sophomore after bringing my gpa up next semester? If i recruit now would it look bad to recruit for the same firms again next spring as a sophomore? since they do have applicants' info on file and it prob shows that i applied as a junior but applying again as a sophomore