i don't read flash so i don't know, but i can find it realistic that drawing on the speedforce dramatically weakens someone. it's like working out really heavily one day. pushing your muscles further than you ever have. the next day you're going to be sore.
Do you not see the problem with The Flash? You find it realistic that limbs could move at the speed of light, when in reality, they would be atomized.
In the 80's, after Barry Allen died in Crisis, Kid Flash (Wally West) took over. He was more interesting, because he couldn't crack the speed of sound, and had to eat like 100,000 calories a day. He could only move as fast as the energy he had stored. He had to raid a Taco Bell once, in the midst of an extended fight. Literally, his kryptonite was malnutrition.
Then the scientists told him that he was burning more calories than he was expending, and that he must be drawing speed from somewhere else. That's when it all got screwed up, when they helped him tap from the speed force. He got uninteresting at that point. When he got to the point he could vibrate his molecules and not be hit, and he could put anyone in a state of suspended animation just by looking at them, is when it got FUBAR.
In the same way that Iceman in Marvel is the biggest slacker in that universe, so is the Flash. Iceman is omega level. And let's face it, if Flash wanted someone dead, he could vaporize their atoms with one infinite mass punch.