1 - Allow players with shared internet to play on different teams.
Change server cvar sv_allowEnemySameIP
from 0 to 1.
Changing this, however, will allow cheaters (with more than one Savage open on the same PC) to join the enemy team as spies, afks, or fake voters to win the match easily for their own team, completely ruining the match.
I suggest enabling it ONLY TEMPORARILY while there is someone around that needs it and disabling it once they're joined again.Enable at your own risk.
2 - Put the time of the game to run decreasingly, without limit.
Not sure what you mean by "run decreasingly" as that's already how a time limit works.
You can't have it run decreasingly and without a limit at the same time.
Perhaps a mistranslation on your part, so please elaborate.
But try changing sv_timeLimit to 0
to remove the time limit entirely, turning the match into endless mode.
There is no risk involved; destroying the base or using votes can still end the match.