Well I think that the mod should try to be as close to the original Renegade as possible, with few additions making it improved. Multi-player on the original Renegade is already very fun, so we wouldn't want to change it to the point where it's not like the original anymore.
As for time limits; I think if the time is set for 99 minutes then there really isn't any problems, it keeps the game as if it were infinite time, but if it takes ridiculously long then it will end there.