I am worried a little about the potential of Chlorine or any other impurities leaching into the bath causing contamination. Any help would be greatly appreciated. You didn't say, but I am assuming that you are using an acid copper bath for plating. I would make the tank out of PVC and use a molded PP liner for best performance.
Glued joints work fine in an acid copper bath.
Welded joints will hold up for a while, but, in my experience, are not optimum, which is why I suggest a molded liner. Given the size tank you are talking about, rather than using ribs, I would simply band the tank a couple of times with something along the lines of a ty-wrap tightly. No, you must NOT glue on outlets. They will fail. You have two options.