While you bash pretty hard on the level, you give very little information what exactly is wrong.
As far as I understood, this game targets mainly child’s till the age of 14 (roughly), with nice Graphics and simple commands. As early-20 IT-Student myself I’m highly overskilled for most levels. But even I find some gems which are pretty hard to solve, when restraining myself to lower gear (because I don’t have the gems for better gear) or targeting high-scores.
So as you seem to not be a part of the target audience, this game maybe simply isn’t something for you. And if you got to Sarven Sentry, you actually encountered a lot of
kiddy game crap, so I can’t really see your point. The whole dungeon-area is
kiddy game crap compared to this.
Now to flags: While it is pretty hard to play a level with flags when there is really much action going on, Sarven Sentry is not one of them. I tested the level on multiple browsers, and while I can not say that Chrome is the ultimate solution, it works there. Also in Firefox, which is fast for me as well.
Placing flags is extremely easy. Once you submitted, you can use Hotkeys to select the flag you want, and the scout’s reports give you enough time to switch the flag (even without hotkeys) and place it. If you do not wear reinforced boots (which slow you) you can even issue the command once the enemy is visible, though I would call this the hardcoremode of the level.