The version of BearShare offered at Gnutella forums is the BearShare 5.1 Beta (released before BearShare was sold to MusicLab), almost equivalent to the 5.1 Pro version of that time. This version runs on the Gnutella network, not the iMesh network like the much later MusicLab, LLC versions. The BS 5.1 beta is clean, unlike the MusicLab versions.

From memory, it was the 5.2 version where the kill switch was added. Could verify with a forum search I guess. I think 5.3 was never released, I'd need to confirm with my previous private discussions with File_Girl. Though there was a 5.3 version that had been started to be worked on by the BS developer before BS was sold to MusicLab. I recall seeing a BS version development page.

As for this forum being blocked by some lists, yes that has been a known issue for some years. No idea why, the site is clean. Once listed on some block lists, those blocklist maintainers rarely remove them. Thus their list simply grows & grows larger & larger with lots of innocent victims included.

Feel free to try out the BearShare 5.1 beta, else there's several other gnutella clients you can try. LimeWire (or LW Pirate Edition), FrostWire (similar to LW), Phex, Gtk-Gnutella, Gnucleus, Morpheus, ShareAza, etc. Both Phex and Gtk-Gnutella are gnutella clients still being actively developed. LPE has temporarily gone into hiding with a name-change whilst they get their next version out (no idea when they will release it, could be a while.)