Yes, You can. However the charge is 1000 THB Per Lesson and should be booked minimum 4 days before the class

You can cancel 2 Sessions in 10 hours course. However, you should inform about it minimum 2 days before the session. Last minute cancellations are not allowed and would be chargeable.

Two times per 10 hrs.

Yes. Every package is valid for 4 months duration. So, you must finish the classes within the 4 months.