It's a good idea, but not so simple
On UKScenario we have had team directories, a captain/point of contact directory, player maps and google maps of paintball sites with scrnario events and retailers.
http://www.ukscenario.com/forum/viewtopic.php?f=3&t=15181
http://www.ukscenario.com/forum/viewtopic.php?f=77&t=29785
There is some 'controlled' information with things such as the paintball awards (team captain / pocs have the opportunity to contribute with the initial nominations) there is the ukpsf which is the equivalent of a 'governing body' but there is no enforcement power or require run to be ukpsf members etc
A problem with online maps can be that the person who puts in the work putting the info together and creating the map can end up owning it and either has to maintain it or it falls out of date. Not so bad for a map of the shops as it is reasonably static, but every new player or new team becomes missing data - even if they add themselves to a list but it does not get updated.
There have been maps where people can add themselves, these have usually been part of the website or using 'advanced' software APIs for google maps etc rather then just being a google map.
Eg specops paintballs brigade software in the us forum and either they or another us forum had a google style map which sounds similar to the skate forum map mentioned above.
A problem will be gathering the information, putting it together and maintaining it. There are numerous forums, not everyone uses forums - just in the uk, let alone the world.
It would not be a solution to the risk of picking a name that is already in use.
Anyone can name themselves, there is no 'authority' to control the names. On a tournament basis (I understand) that there is a form of control that if you enter a league such as the millennium you register the team, so would discover that it is already registered. But that does not mean the name was used before, the team that registered first existed first or that various teams already exist with that name that are not competing.
In the world of business it is accepted that names may already exist and can co-exist. Eg apple can do nothing about any other company name apple. There is a form of protection for companies in the same line of business and for 'confusion' that may be caused.