To close as solved I recap:
1) how do you overcome the nightmare of having different audio formats for different browsers? (especially with ios's safari).
2) When you make a webgame for pc and also for ios web browsers, how do you manage the dual controls scheme when there's no 1:1 correlation between pc controls and ios heavy use of touchscreen?
A)
1)All audio problems are easily solved in any situation/device/platform just using Construct 2 dual-enconding feature (W7 Only) and wrappers for ios browsers. Dual-encodig works in any situation.
2)If controls are easy to replicate then use C2 methods described in tutorials and blog. But if the controls are too dispar then a dual project could be more manageable in the long run.
Workflow for webgames so far:
1) Develop for pc, keep controls in mind if you intend to export to ios.
2) If you develop under windows 7, any audio issue across browsers and devices will be automaticly fixed with C2 dual-encoding feature.
For other OS, you need to do this by yourself.
3)When you want to export your webgame from pc to ios make it as a separate project or see tutorials for ways to detect devices and use only one project/code for any end device/platform.
4)Export your final project to ios using a wrapper, PhoneGap for easy casual browser games (given it's slow) or directCanvas/CocoonJS for speed and more "native" games (as those doesn't use ios browser).
THE END
Thanks Ashley and Sqiddster for your atention to my questions!