Questions about HMC1121

Hello,
 I am working in a design and looking for a PA with 5.1 - 5.9 GHZ  frequency range .
The HMC1121 PA looks great but I have several questions about this part:1.- Frequency range is 5.5 - 8.5 GHZ but  plots on page 8 show the behaviour from 4 - 5 GHZ to 9 GHZ. Could I have a problem if this part is used from 5.1 GHZ to 5.9 GHz?2.- In the absolute maximum ratings table, the thermal resistance (Rth) is 4.4 ºC/W. is that right?. I am asking that because in a similar packages I saw greater thermal resistance.3.- About the same maximum rates table: there is not limitations on maximum and/or minimun voltage for Vgg on this table. How could I get those values?
Regards,