std. halogens vs. blue/white halogens

[pjc01]

got some questions here about halogen bulbs :

1. aside from looking really unique, are there any merits to having the standard bulbs replaced w/ blue/white ones? do they really increase visibility.

2. is there a big difference with those halogens that say 'high visibility' than the OEM ones?

3. i've never tried changing my headlamp bulbs and i saw in the manual that there needs to be more tinkering done - do i have to have the headlamps aligned after i replace the bulbs and return the assembly?