the quality of unconditional love (and the ultimate line switch) was the result of a missing master. theo (from the all about u video, and l.a. radio personality) was given the song to play on the radio and where the master ended up from there is a mystery. the "she still loves me" line was tagged over by the station, and that's why the line was removed for retail release. i suspect that amaru was able to obtain an in-house archival recording of the airing by the station and layered some instrumentation onto it, thus the quality is superior to radio but far from cdq.
i'd argue that unconditional love was not an example for hammer to use since it's very much a finished track. hammer's version doesn't use the same singers, and moreover the lyrics reflect pac's life much moreso than hammer's (despite his occasional word changes).
as for let's fight, the yaki mixtape version is the audio from a recording booth camera (the footage snippet was originally leaked for hitemup vip members), and while it may be a little different sounding, it could be the dynamics of the sound (a nickel sized camera mic and lots of in-booth chatter) or a different take. the acapella has a whole mess of talking in the background, so i wouldn't be surprised if the yaki version and the recently publicly leaked lp version are the same take, but captured by very differing mic's.