It may be possible, but might not be 100% reliable. I could look at checking the IP address for 10.x.x.x or 192.168.x.x but these don't always mean local - what with ISPs performing NAT, and VPNs.
There is not much that can be done about that - if a user has a slow Internet connection, or they are on the other site of the world, they will have a high ping. This plugin prevents problems caused by a player's PC sending too much data for the server's Internet Connection to handle, not problems caused by players with crap connections.
You should not run this plugin unless you are experiencing the problem it corrects - specificly that the ping times of all non-local users connected periodically rises to 2000+ and stays there until you kick the player that just joined. I would expect you may need it if you have a 128K upload line, a 256K line with more than ~6 players of a 512K line with more than 12 players. In practise whether you need it or not depends on how manu players simulatenously try and join with high rates.
Don't know - never measured it! Logic suggests it would a little, but it is not designed for this purpose.
A: The plugin increases mp_timelimt by 5 minutes more than the plugin currently believes the time on the map should last. This is to allow time for the voting. The increased time limit provides a fail-safe should the plugin go wrong to cycle the map 5 minutes later. If the plugin is disabled with "bb_mapvote off" the original value for mp_timelimit will be restored. This may cause an immediate map change.
A: There is a setting in server.cfg vote_freq, which is the number of seconds that must elapse between votes. This includes all forms of voting that display a numbered menu - not just those from this plugin. If the round time expires or someone uses rock the vote too soon after a previous vote of some kind, these errors will occur. I recommend setting vote_freq between 90 and 180 seconds. The more plugins you have that use voting, the lower it should be.
If you continually issue votes from other plugins the end of round map vote may never occur and your maps will cycle normally 5 minutes after the specified time limit.
A: If you used admin_map or changelevel to change the map, the plugin does not track the change. This may also occur for the first map after the server starts. This will be fixed in later versions.
A: They have been disabled to prevent players circumventing the voting options you have selected - in particular banning the last n maps.
A: You must put the plugin_blattvote.amx line at the top of your plugin.ini.
A: Let me know why you want to and I may implement it.
A: They were written for version 2.50.26 and at the time of writing have not been sucessfully tested with any other version (to my knowledge)
A: They were written for and tested with counter-strike. However, I have recevied an email from a server admin using them sucessfully on Team Fortress Classic. The rate management plugin in particular should work on all mods.
A: Read/watch the "Hitchhiker's Guide To The Galaxy". Or visit the online guide.