I wouldn't usually double post but wasn't sure if you were subscribing to this topic panda and the edit might not have come up.
I tested the plugin again on a packed 30 man server without the weapon_flashbang in the t_spawn/ct_spawn and everything was fine until the grenade level. Everything was ok at first and then about half way through the round the server crashed. I rebooted it and we tried it again (on a different map) and once more everything was fine until the grenade level where it promptly died again. I had it on infinite grenades with sm_randommadness_grenade_count 0 and don't know if that had an effect considering the amount of people on. I thought I'd let you know as maybe this unique way you're handling the grenades is causing some sort of issue.
As an aside when it was working everybody on the server was absolutely loving the plugin, so if we can iron these bugs out you might be on to a winner!
Let me know if you need any more details.