VS2012 has better syntax highlighting than VS2010; classes, namespaces, typedefs have colors now.
I imagine VS2012 would be a little bit better than VS2010, afterall it's newer, so I guess it might have better auto-vectorization, new C++11 features (move, etc) should make it better as well.
IDE itself is responsive. No problems that I haven't had with VS2010, sometimes random freezes, intellisense messing up, etc. Restart fixes it most of the time.
There's no way to connect if your address is dynamic. You need something static. The only thing that comes to my mind, use free website host or file host that allows direct linking (Dropbox for example), store .txt file that contains your current IP address. Client program could automatically load the page, copy address and connect to it. But you'd have to change it manually everytime your IP changes (unless you make another tool which would do that automatically).
Use bigger buffer or use dynamic buffer which increases everytime it overflows. Eventually it'll reach max size when it stops overflowing, however it might end up eating whole RAM if you have bug somewhere.
Visual Studio 2012 IDE is much better. Eclipse/Netbeans are only comperable to Visual Studio 2010 (it had only keyword coloring), while VS2012 also colors #defines, classes, structs, typedefs, there is possibility to configure appearance of methods, local variables, fields, params/args, global variables. I've Googled a lot but VS2012 is best you can get, and it's even free for 'basic' version.
output.normal = mul( input.normal, _wvp ); You need to transform normal by inversed transposed world matrix. But if it doesn't contain scaling, it'll be equal to float3x3 part, meaning you can just typecast. If you transform by view and/or projection it has other meaning, and it breaks your point light.