Its something for radio noise. You can remove it. For AFR run it the mid 11s is pretty safe, no one can really tell you what timing to run. I always start pretty conservative and ramp up from there until it either starts to knock a bit or I feel comfortable where its at. I would recommend tuning ignition timing to much without some way to monitor knock. I currently use some rigged up Det cans (google those) and they work very well. Ill probably be upgrading to knocksense pretty soon tho
