if u check back few pages my lumia is always dead if on long standby...then i send to nokia care to update to latest portico and walla im not having any of that issue anymore.been 3 days with no prob whatsoever 

so i think yes it will fix most of the prob of the old firmware

We chat heat up the phone quite fast too   

because you have more than 1 email asign to your wp8, each contact create will save to your selected email's contact.

just select your primary emails will do.

ex,

My WP = my primary email + my wife 2nd email

My Wife WP = her primary email + my 2nd email
we both share the same contact list on our devices to keep both contact updated.