You can probably get by with a single lip seal for a couple of trips, though not if your pulling long distances. The water basically vacuums into the hub when it cools as you launch the boat. When that cavity cools it sucks water into the hub through the single lip seal. The tension on the outer bearing nut is just snug, not tight, just snug it up. Not loose, just to where the play is gone and the bearing are seated and still turn easily. It does not sound like your too tight now, though perhaps too loose. The bearing buddy cap you should score the outer lip with a cold chisel starring the lip to increase grip. The cap must go on square, and use a block of wood and a large hammer to seat it once you have it lined up. Do not tap it from side to side, like you do when you remove it, this rounds the edges, which the scoring the edge sort of gives you more bite. When you tap it out you round it, and the replacing it should be fast and firm.
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