1. If you Uninstall Netscape, both the Browser and the Mail client are removed. It is a package deal. You do, however, have the option of not deleting
your data.
2. I don't have Netscape 8. When you installed it, did it give you the option to set it as the default browser?
Look in the Registry at
HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet
the data there is the name of the browser that is the default. On my system it is
FIREFOX.EXE
But there is also a sub-key for each of the browsers installed on your system.
I have three:
firefox.exe
IEXPLORE.EXE
Netscp.exe ----- [I have Netscape 7.1]
Note: There is a similar but shorter set of entries under HKEY_CURRENT_USER. Internet Explorer may use that for per-user customization. The Mozilla products seem to be inconsistent in setting, checking, and honoring the settings between HKCU and HKLM. I don't have it straight.
If Netscape 8 also uses "Netscp.exe" as it's key value, then I would guess that there is no way to differentiate between NS 7 and NS 8.
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.8) Gecko/20061025 Firefox/1.5.0.8