HI Alex,
I will try to answer your questions but I do not claim to have the definitive answer, as I am "just a practical user" and not a designer or expert on SV.
1. SV will work without the AHRS hardware, but it will give LIMITED bank angle information. For the $15 upgrade and easy installation, a person can have the full capability of pitch, yaw and roll axis info (acting with the GPS).
2. Again, limited depiction - where WITH the AHRS hardware I will get the full 60 degree bank indications on SV, I will not get that without the AHRS chip. Maybe 30 degrees?
3. The IFly IS linked to ADSB traffic and shows on BOTH the sectional (or whatever you prefer to depict) AND the SV view. I have posted many photos on this site showing that very feature, so please feel free to browse around and view them for your edification. Great questions and thanks for checking in! Again, I am no expert - these are opinions based on actual usage over a 4-5 week period.
Mike