Q. What would happen if I use traction control mode 1 in Kawasaki Ninja ZX 10R on the streets?

If you keep it at 5 , more frequent engine power will be cut if ECU sensing loss of traction, that means more aggressive cutting , more safer (depending on terrain ). So its better to keep at 3 normally. Depending on the condition of the road you usually use, you may set it. From this now you can guess how bike will behave if you keep it at 1. So when you loose traction power will be reduced automatically , Example , level 1 - 160 HP, Leve2 - 140 HP, Level 3- 100 HP, level 4 - 80HP, level 5 - 60 HP like that only available when system kicks in.