The way I see it currently, Flashtime isn't a mode, it's just the Barry's best feat in the series (by dozens of times) happened in an episode that made that implication. It's probably because that was, like, the most desperate we've seen Barry in the series. Anyway, Bloodlusted Barry travels back in time and kills Kara before she was born. It's not like she can do anything about it since Barry can statue pretty much everyone in LACM sans Smallville characters and maybe Reeves.
My knowledge of Thing is limited to F4, fighting Hulk, and crushing a weight. The second thing is more than enough to actually slap the dudes, but I'll go do a bit of research before saying anything definitive.
Well, New 52 Superman traveled from the edge of the universe to Earth in 60 days, and just the distance to Andromeda is 2,537,000 light-years. Traveling that distance in 60 days is roughly a half a light-years per second if I didn't mess up my math. Half a light-year is 2,939,000,000,000 miles, and that many miles per second is equal too >15,0000,000x lightspeed. I don't think any of those feats are even close to a million times lightspeed.