Hey,
Thank you for letting us know about these issues, most of these are already known and being worked on, but I'll provide a bit of context to each.
This is not server sided, it is due to the maps and their interaction with CS:GO. Since the panorama update, support for LDR (low dynamic range) maps has dropped, which means that maps that were complied using LDR have the potential to crash a user's game. Unfortunately, most popular aim maps are compiled with LDR, including am_banana, am_grass2, am_nuke_32 and more, and so the only way to fix this is to remove them from the map pool or find replacements. This is currently being looked at and replacements have been found for most, but in the meantime, everytime you SWITCH maps, so JUST BEFORE a map ends, type retry in console and it will prevent your game crashing. It's a temporary fix, but it's worked 99% of the time for me.
!ws takes some time to update, especially because this applies across all KZG servers. It will take some time to update the skins for !ws across all 38 of our servers, however, I'll let the appropriate staff know so they can look into getting this in :)).
This used to be a problem on the OCE 1v1 server, but it was fixed a couple of months ago, I'll ask the appropriate staff if they can get this fix applied to the 1v1 SG server too. As for now, there's the temporary fix of turning off those rounds, but obviously that's not what we want. Also, please let me know if the HS only round with an assault rifle + pistol (normally AK-47 with P2000) allow you to kill enemies without headshots.
Thanks for taking the time to write this, and have a great day!