Craig, This is myu opinion on the loose barrel loop. No the barrels do not have to be completely re-soldered. Just make sure that they are not loose by careful inspection with a jewelers loop or magnifying glass. If everything is sound the first thing I would do is to take ordinary blackboard chalk and go around the outline of the loop. On a toothpick put some rosin on it and go around the loop. Take a propane torch and heat the loop and touch some solder near where the two meet together. Take heat away when solder melts and see if it goes between the two pieces, cool with a wet cloth and see if loop held. The chalk stops the solder from migrating from the area. If it didn't work, it is because the bluing is stopping the solder from sicking. Then that small area will have to have the bluing removed. Easy touch up with todays spot touching blues like Oxpho Blue by Brownells.
The top lever could be that the spring under the link is weak or broken and not enough tension to hold it shut during recoil.
The three position safety sounds like when the stock was off someone missed putting the safety link from the trigger housing into the slot of the safety and is now in front of the safety slide.
Remember these are my opinions and this is what I would try first. When owning these older guns, unless your pockets are very deep, it helps to know what makes them "tick" and not "tick" by opening them up and looking and seeing how they do work.