Do you mean Google Chrome vs Chromium, or the stable, beta, etc. versions of Chrome?
Unless you enjoy beta testing or are a developer working on stuff for the browser, I suggest google-chrome-stable.
For the welcome box, try closing it, then opening a terminal and typing in "mintwelcome".
This should open the welcome box. When you make this one freeze you should get output on the terminal which gives more info about the problem.
PC: Manjaro/LM 13 x64 XFCE, Kernel 3.11.1-6/3.8.0-32-generic, Nvidia GTX650, i7 3770K, 16GB RAM, Asus Xonar DX
Laptop: Lenovo G560, LM 13 x64 XFCE, Kernel 3.11.1, i3, 6GB RAMMy HTML5 login themes + screenshots