Gluvit won't seal the 100's of rivets through the ribs, only inspection and replacement will. Also the keel valley takes some special attention. Then of course the leak test after you think you have everything sealed up. Transom attachments, sealed up with 5200 should never be an issue. If you have back wash coming into the SW then it should just return to the lake through the drain tubes if everything is sealed correctly.
My SS did not leak a drop on the leak test yet due to the water pressure fully loaded and under way I ended up with a cup or 2 of water at the end of a 8 - 10 hour day never enough to kick on the bilge with the float and not enough for the pump to pick up..
The big issues with large leaks is rib end crack and the spray rail splitting.