Hi Pierpaolo,
1. How to set HSRUN mode?
Please add a new component in Processor Expert and new a Power mode configurations as below.

Then in the code call ROWER_SYS_Setmode, and fill in the power mode index which indicates the HSRUN mode, in my case it's 1.

2. How to set RUN mode to 80MHZ from 48MHZ?
Please set SPLL_CLK - Multiply to 40 and choose SYS_CLK RUN mode to SPLL_CLK/2.

3. How to know your current system clock frequency?
You can use the clock output feature.
In PIN_MUX component you can set maxim 4 pins as clock output

Then go to clock manager component, choose the clock source you want to monitor

Hope it will help. Any question please feel free to reply.