I'm sorry, this morning i was a little aggressive lol.
What i wanted to say is that DWN is a great game(a big surprise for me and one of my favorites on vita) and the touch screen stuff is really non invasive, it would be a shame to miss such a game(for free!) for such rare and short stuff, in a 10 minutes mission IF you find an ambush(most of the times you don't) it lasts a pair of seconds and as i said you don't die if you fail it, and the duel with the enemy commander lasts 20 seconds only if you don't know what are you doing lol, and again if you fail you need only to redo the duel, not the entire mission like in the case you die on a normal fight.
Those are the exact opposite of invasive and DWN is not a collection of touchscreen minigames like you are depicting it("my time and storage space is limited so if I have to put up with touchscreen minigames, I'd rather avoid it") but a real DW game with even new exclusive features like character creation.
DWN is a really well thought game, tailored for Vita, one of the best looking games with beautiful native res graphics + (4x?)AA and everyone should at least try it imo, the presence of touch screen stuff is absolutely not an excuse imo, but do what you want.