The steering knuckle will throw the grease outwards, but will pick it up whenever sharp turns are made at the wheel. Just stuff as much as you can in there and you will be more than fine. The TM calls for pumping grease into the zerk fitting at the bottom of the knuckle every 1000 miles which is fairly often, so it will well lubricated. IMO the CV joints do not need a full on bath in grease to be properly lubricated, enough of a film will do the job and as I said earlier, the grease is occasionally redistributed throughout the ball bearings whenever sharp turns are made.
The reason for the inner axle seal leaking so often is due to the trucks sitting for an extended period of time which may create a little flat spot on the seals lips. These were not intended to be wet bearings, but minor oil leakage past the seal is normal especially if your doing off roading. The gear oil from the diff may splash up into the axle shaft housing where some may leak past the seal. Also, if overfilled the seal will not hold up too the extra oil. I overfilled mine by accident and in 2 weeks gear oil had made it's way past the inner axle shaft seal, into the knuckle and into the wheel bearings.
I like your method of using two thin axle seals. You should be leak free for a long time.