1st to 2nd slipping/quick

That's an odd one but like Trailbeast I'd start with checking the front band adjustment. If it's real loose 2nd gear shift will be mushy. The only thing is it's usually delayed when the band is loose and you say it shifts real fast. The 1-2 shift spring in the valve body could have lost tension making it go into 2nd real fast but that still doesn't explain it being a soft shift. I wonder if the guy screwed up something when installing the shift kit?? Give the band adjustment a try and report back. If your not familiar with adjusting the front band let me know and I'll post some pics and text.