I'd actually be kind of okay with that, maybe...the only way I've ever been okay with Jay's existence is if he's from a parallel earth, I prefer to try to keep it to as few speedsters as possible in our reality as Flash's accident should be a super rare, one time thing (it's a lightning accident for cripes sakes). And I'm aware Wally has just about the same origin Barry does as far as powers go, which has always been one of the weaker elements of The Flash mythos for me, so I would tweak that a bit or provide a more logical explanation for it at least like Geoff Johns did (well logical for comics at least)... But if Jay had to exist in the same world Barry does, I wouldn't be entirely opposed to having him be nonsuperpowered, your line of thinking isn't bad....I just really like Jay with powers at the end of the day, lol, so I prefer he be from Earth 2 and Barry accidentally discovering it while doing something new with his powers he's never done before in his "Year 2" as The Flash....although having Jay come to our realm on his own to warn us about something would be interesting in it's own way, I'm just not as much of a fan of that because it robs Barry of having discovered the multiverse, which is one of the biggest and most important things he did in the comics and comics history as it'd become a mainstay of DC Comics for years and a HUGE basis for many if not all of their stories later down the line. The Flash/Barry Allen has a unique and special place in history.
