safe MICRA K11 WHEN TO SHIFT AND SAFE RPM

[AdaZara]

Hello, I am new here and you are the one who is experienced, so i thought u could help me.
First of all, I own Micra K11 1.0 16v 40 kW,
I dont have rev counter so I am not sure when to shift up or down. Sometimes I had feeling that car is gonna blow up because i am reving it too much, everything is stock so rev limiter is here (i dont know if 7200 RPM or what).
Is it safe to rev 2nd gear to 80 km/h and third gear to 120 km/h ? I mean if its not gonna hurt the engine.
And then I would like to ask if is it better to reach top speed with 4th or 5th gear, what is faster and what is safer ?
Thanks
PS : sorry for my shit english :-D

[Trevor]

I would change from 2nd to 3rd around 70kph (maximum) and then to 4th around 95kph (maximum) but there is nothing wrong with working the engine as long as it is maintained and the revs are not sustained for too long.