Is squamos cell carcinoma of tonsils cureable?

Yes. It may be curable but you will need and extensive work up and close follow up with your otolaryngology surgeon (ent). Depending on the extent of cancer treatment may consist of any combination of surgery, radiation, and chemotherapy. Maintaining your nutrition and mental health during this time would be very important as well.
Possibly. In addition to thed size of the tumor and whether or not lymph nodes in the neck are involved, a test for whether the tumor is hpv positive or negative is very important. Hpv is the human papiloma virus. If positive the cure rates are good to very good. If negative the cure rates are fair to good. Also a ct scan of the chest is important - whether the tumor has spread or is another tumor there.
Depends. This is dependent mostly on tumor stage. In other words how big the tumor is and if it has spread to lymph nodes or ther sites. Early stage tumors can be cureable whereas later stage tumors often are not.