[What in the Gods Names is with all the Teleport Issues. the constant restarts. the seriously bad lag]

For reference while watching my bandwidth meter I am finding most frequently 1200 to be a load bearing number where 256-mid 500's just spinning around in welcome areas. This also assumes that I have my graphics up all the way with almost every high end graphic option enabled in Kirstens Viewer 21 r5. I keep my max bandwidth at 5000 and keep my cache at 1024.   

While this may not give you a direct answer it gives you an example of what I use to help you fine tune your viewer.

[What is Anisotropic Filtering?]

Great quote usage.

[My Second Life causes my entire network to slow-down?]

Keep in mind that your SL does have a bandwidth option where you can configure how much traffic you are going to allow SL to generate. Your total network usage can vary based on what sim you are on, graphic settings (textures/etc) as well as overall draw distance. I have mine set really high and on average in a busy sim while loading I can see it tap on 1Mbps but generally hangs out at 375kpbs.