Picosecond is a scale of time. GR's attacks still happen in a given amount of time. GUESS HE'S PHYSICS :P
Speed Force outright defies physics because you can go faster than light, ignore friction, ignore g-forces, ignore molecular cohesion, vibrate through dimensions, time travel backwards and forwards, create matter out of pure energy, etc etc. While its effects are frequently explained with physics, you can explain a lot of non-physics based superhero nonsense with physics even if their powers aren't based that way.
I mean, the Speed force is an infinite extradimensional energy source, nothing in physics that explains infinite energy in an alternate dimension.
Just because someone's powers are magical doesn't automatically make them better. Odin's powers are magical, would you say he beats Galactus, whose powers are sciencey? Course not!
That said, as I've admitted, Wally can't hurt the GRs (though apparently you can still use them in street level tournaments :P) so it's moot
FTL is not defying Physics. Students of a University already made a Laser that moves 3x FTL. It is not Speed Force. Infact everything you mention Science is trying and coming close to make theories about today.
Also can you measure Soul Burn for me? How about the energy of Hell? The Pain Damage of a Penance Stare?
Flash feats are mesurable by Science of today. GR Soul and Hell powers are not.
Magic/Reality Warping > Speed Force/Physics.
Now we are arguing semantics. :P
I'd like a source on that FTL thing -- I've heard of a few universities claiming FTL experiments, but they've all been proven completely false because our instruments don't actually calculate things faster than light. The only time anything's gone "faster than light" is when Light is slowed down (like in, say, water) and they bump an electron in the water to move faster than the light, but still slower than the c constant.
If it's the experiment I'm thinking, they shot it cross country, through a mountain range, and it "beat" the time it would take light to get there, but under further scrutiny it was an error in their calculations. Every claim of "FTL" in real life has been debunked or is currently under scrutiny for lack of evidence.
I think you're being silly attributing EVERYTHING that is magical to being better than everything that is physics related. Like I said, Galactus is way more powerful than magical sky fathers, and his powers come from eating energy from the universe (IE physics) in a way that is quantifiable.
also, come on, one of Wally's most notorious rogues is Abra Kadabra, a reality warper, and he beats him all the time. (This is the guy who can literally erase a person from ever have existing throughout reality, like he did Linda), so don't tell me Speed Force can't beat reality warpers.