I have noticed this as well. But it has gotten better over time, and once the phone gets a lock on GPS it holds onto it quite well. I have also found that enabling Verizon and Google location services helps the phone acquire a GPS lock more quickly because the phone will look for cell phone towers to help narrow down your location. Every now and again Navigation will even ask me if I want to allow it to use wi-fi to help narrow down my location even more.
I've also noticed that sometimes cloudiness can significantly increase the time required to lock onto enough GPS satellites to provide good location information.
As for rooting and such, it is possible for a phone's user to run special computer software while the phone is connected via USB. This special software tells the phone that a user can modify certain files and applications that were previously locked out of direct user intervention.
The end result of rooting (which is a way of stating the user has access to the phone's root file system) is that a user can uninstall Verizon bloat like VZ Navigator, Blockbuster, Let's Golf 2, Rhapsody, and all the other bundled apps that very few people ever use. Getting rid of them frees up phone storage for apps you actually want and also keeps these apps from running in the background and potentially using too much battery.
A rooted phone can also have it's ROM replaced. For the Spectrum, this means that a user can completely wipe out the LG Optimus UI and replace it with Broken Out Spectrum. Broken Out is much smoother and quicker than the stock UI.
Broken Out also includes a custom kernel, which is the basic system software that regulates basic hardware and its interaction with higher level programs, like apps. This custom kernel allows the phone's processor to work faster and with lower voltage than the way LG originally set it up. Faster would usually use more battery, but the lower voltage offsets that and battery life supposedly increases while providing significant increases in performance.
The whole process of rooting and changing the ROM sounds complicated, but it's not as bad as it sounds. But doing these things violates your phone's warranty. On the other hand, the same tools used to root and ROM your phone can be used to return it to its stock state without any evidence that it was ever messed with.
If rooting and ROMing sound intriguing to you, read up on it here and on other forums. If you find it's something you want to try, we'll all be here to help.