If I set Fusilier Dragon and I flip summon it on my next turn, what are his points - 2800/2000 or 1400/1000 ?

His points would be 1400/1000 if he was set without tribute and then flipped face-up. That information is right from the FAQ for individual card rulings Fusilier Dragon the Dual Mode Beast. This has alread been asked a lot before buddy, you should use the Search function before making a new topic. Also if there's something you are not sure about you can check the oficial website's FAQs before posting anything here.

yep, to reset fussilier to 2800 you have to flip it face down and face up. if you set it then you never flipped it face down, you'd have to flip it up, then down, then up again to reset it.