You don't have a choice, the pink cable needs to connect to the rear lights or any positive to the key to supply the unit with power and the black cable needs to go to a ground. I tried not connecting some of the cables and the alarm didn't work. the blinkers are just 2 cables and since you have to connect to the rear light and ground may as well connect the entire system as it will make no difference in space.
The only thing you can leave off is the kill switch, that will save you a bit of space but I like thieves not been able to hot wire my bike.
You also have the option of not connecting the proximity sensor and that should save you some space.
By the way, if you bought the cable kit for your bike, it makes install easier but it adds a crap load of cables and takes away a lot of space so don't use them, just strip and connect to the wires directly would be my advice.