How it works is when moving at speed, the tp comes at them 'slower'.
There was a comic where Grodd was trying to paralyze him with horrific visions projected into his head, but because he kept moving he got a brief flash every few seconds (his perspective, not real seconds) instead of an overwhelming attack.
So Flash is affected by telepathy in the sense that his brain doesn't have special immunity most of the time, but when hyper-accelerated it can basically process each part of the attack piece by piece and so not be nearly as affected.
Greater DMG output? What's stopping Manhunter from just going intangible and Invisible and Flying out of Wally's reach and firing off ranged attacks? Or throwing a mountain on the battle field?
The fact Wally should be much faster then MM, and steal his speed..
Plus, the speed force is such a plot device, it can probably affect his intangible form. Johnny Sorrow was intangible, and Jay Garrick took him into the speed force along with King of Tears.
And since you apparently going CBR style with John, I think it's only fair that the same should be applied to Wally. In which case he takes it 10/10 every time.
Wally has to find MM. Invisibility and the ability to change shape would make that impossible. Wally isn't a telepath. And even if John can't take over Flash's mind, Flash is still subject to a good Psy Bolt to slow him up. Even Zum was using his powers to much with Wally's powers.
Once again, if we're going the CBR route, Wally wins every time. He'd have John beaten before the thought of going intangible or invisible even entered his mind. John would be nothing more than a frozen statue that he'd drain the speed out of and toss into a Volcano.
Who said Wonder Woman was the only hero I read? I'm not going cbr because I don't know what that is. I'm going comics. MM knows about Flash. So it's not like he would go into this without knowing flash. a Telepath is a great defense against a speedster. Especially when that Telepath has a high amount of Superspeed himself.
Wally claimed he could stop Superman cold when he was being chased, but didn't because it would mess up the environment..
In a battle, a speed steal should be near instant, considering he's starting out with greater speed.
Also, there's a feat of Wally seeing through invisibility by moving at near light speeds, which somehow alters his perceptions.. (Which makes sense, since he'd be blind at light+ speeds otherwise..)
The question is, has Wally ever stolen the speed of a being in complete control of thier own molecules. Which is all Wally is doing. Slowing down molecules.