I'm a 25 year old male and have been going through something very similar since Late July/August 2012. Hope my answers to your questions can help. More like opinions and comparisons to what I went through. Good luck and keep us updated!
1.) I had a full exisional biopsy done on my left sub mandibular lymph node done 10/12/12. Took 2-3 weeks for results to get back. Mine came back negative with no definitive signs of malignancy. They could not diagnose me yay or nay really. If there are cancer cells or strong indicators then yes they could just say you have cancer or they could say it was more agreeable with some sort of reactive disorder due to infection. Doctors notes below. And now 5 months after my surgery they are still "monitoring" to see if anything has changed since they never were able to give me a real diagnosis. Nodes have since decreased in size but are still enlarged and I can feel them.
"The pathology identifies morphologically follicular lymphocytic hyperplasia. Prominent follicular lymphocytic proliferation shows nodular pattern with attenuated mantle zone and inter-follicular zone. The follicular center cells contain heterogeneous lymphocyte population. IHC shows BCL one and BLC-2 negative with BCL 6 positive. Preliminary diagnosis is an atypical T-cell lymphoproliferative disorder. However Dr *** discusses this as most consistent with a reactive lymphocytic hyperplasia. The focal atypical IHC pattern raised the possibility of a follicular colonization. In light of suspicious clinical history, additional flow cytometry studies were recommended to be done on fresh tissue on the indicated. Studies were submitted for B-Cell gene rearrangement by PCR and FISH. The PCR analysis for B-Cell gene clonality shows no clonal B-cell population Dr *** of *** pathology also agrees with this being reactive lymphocytic haperplasia."
2.) If you are expecting bad results I don't see why it couldn't hurt to already have a doc lined up or be at least researching for a good oncologist. My surgeon recommended me to my oncologist after my biopsy even though I didn't have proof of cancer. Was more because he is a specialist in this stuff and has good knowledge on the subject matter. Not for treatment.
3.) I'm pretty much in the same boat as your question here. Not cancer.. Okay then what is it?? I haven't really been poked and investigated that much since my biopsy was done and didn't show malignancy. More of just wait and watch. I have had a few visits to my oncologist since my Biopsy. Only just had a couple CT scans and blood labs to monitor size and my blood counts to make sure the situation hasn't progressed for the worst. its only gotten better
.. as of now my nodes has decreased in size and blood labs are still good. My next follow up and hopefully my last visit to my oncologist is next August a full year after I first noticed the lump in my neck. So this can carry on for quite some time. Never got a solid answer of what caused it. But hey cant be that bad if they couldn't find anything right?