Inactive carrier means that you still have the virus replicating in your liver but it is low or undetectable in your blood.
The prognosis is very good if you remain in this state for the rest of your life although you are still at a higher risk for liver cancer (although I wouldn't lose sleep over it).
That is why inactive carriers should have an ultrasound and AFP (liver cancer marker blood test) at least once a year.
Inactive carriers are considered low infectivity but it doesn't mean you cannot give it to someone. It is just much more difficult to give compared to someone with active HepB.
No, being inactive doesn't mean that you r at a higher risk for cancer. The more active your hbv, the higher the dna, the more prone you are to developing cancer in the near future if you do not seek treatment.
Yes you are at risk for liver cancer regardless of the status but as an inactive carrier, you are at the low end of the spectrum for developing liver cancer as opposed to someone who has active hbv.
Hope I clarified it for you.