Don't buy a CBE for power gains. If that is the only exhaust mod you make, you will be disappointed. The factory CBE is fine until you get heavy into mods. Buy a CBE only if you want a different sound.
From what I have read, an mbc and 2 psi of boost should not be a problem unless you have lots of other mods. There are plenty of people out there who did nothing to gain power beyond an upgraded intake, a better BPV and an MBC set for a modest boost gain, stopped there, got a nice little bump in power and were quite happy with it. Mild mods the ecu can tune itself for. If you have an older model, get the fuel pump upgrade and reflash (assuming you qualify) to make sure it can deliver the needed fuel and you should be fine. Things go to s*** when guys get greedy for power but don't want to lay the groundwork to make it stable.
TMIC and a test pipe means you can probably move enough air that I wouldn't mess with the boost levels without a tune.