My first concern is performance. Will construct2 game run smooth enough on phones to be a good app?
Yes. FPS on cocoonJS is enough, at least for me.
In which resolution should i draw my graphics? If I draw graphics to match iphone 4 resolution for exapmle, and use scaling like in this turtorial will it look good and run smooth enough on iphone 3?
Bigger resolution. I would dismiss all devices below iPhone 3GS.
Third - which html5 to phone coverter is the best?
I would bet on Ludei cocoonJS.
+ is it somehow possible to save game progress?
I guess it is mandatory for any wrapper.
Hear out other opinions, I may be just lunatic.