Thinking an improperly installed torque converter

MPHauto and I have been discussing the bad turn out of my transmission replacement thinking an improperly installed torque converter was my problem. I have taken the transmission back out along with the flywheel and starter. I have some pictures I will be sending. The only visible damage is scarring on the teeth of the flywheel and maybe the starter gear. Can I getbhelp on what I need to be checking to see what may have been causing the grinding sound when I started the truck before putting it into any gear and when it was in gear. As well as why it didn't catch properly when I put it in gear.
Also it may be helpful to know the whole reason for the transmission change to begin with was it took an extended period of timebto catch whe put in drive from park or reverse. So much thqt if on a hill I could roll 10 or 15 feet befoee it would catch. Then it would jerk when it finally caught and then when driving and it shifted from 1st to 2nd it jerked and grinded what sounded like gears then same with 2nd to 3rd.
Please help this has me so baffled and frustrated. I felt this would be a 2 day event then it took a week and turned out poorly.