Verde fontaine care

We've just installed Verde fontaine countertops in our kitchen.  Beautiful!

I've done as much homework as I can online regarding the care and feeding of the material, but still have questions:

1- Is all granite sealed prior to or after installation, i.e. do I have to be concerned about sealing immediately?

2- I've noticed that some sealers are water-based and some "solvent" based.  Is one preferable to the other?

3- Stonetech says that their "Bulletproof" sealer is good for 3-5 years.  Is that realistic?

Thanks for any input.

JF