Missing textures could be down to several factors. Indeed the caching (the first page on LoCFG - brilliant program by the way) is where you will see those, set them to the default values and you shouldn't be having a problem. If your still getting issues it might be worth re-installing the mod and maybe a hard drive defrag (pot shot).
If you have used ModMan to install your mod remove it and re-install it, if you haven't used ModMan slap yourself and then copy all the files over again. Also seriosly think about using ModMan for installing your mods. I would recomend you don't use ModMan's graphics settings though, and if you have in the past default everything and re-set it up in LoCFG.
It might also be an issue with memory, but look fine with what you have. There is another mod out that replaces the textures that Reloaded didn't, it might be worth installing that in case the missing textures are problems with compatibility of the different textures. That is just a guess, but it's worth doing anyway.
As for the sound I would check your volume levels, move everything below 100%. Also check your audigy isn't running in in surround if you haven't got surround. Switch all upscaling off if you don't have surround.
Also you don't happen to be going over mach 1 when these sounds disapear do you?
Regards
Paul