Not so much a spell sword, what with the limited spell selection.

Not sure which Deity. Suggestions?

Depending on what you want. Just like in D&D Paladins can show up for any diety. Which is a bit lame in my view, Paladins should follow Helm and more preferbably Torm (whome you could say was like Tiber Septim) and be of LG alignment. Otherwise it just doesn't feel right. Paladins should be on the forefront bashing in heads for the Good, complying with rigid rules and strict ethos.

As far as TES is concerned, Undead Hunters can go Arkay or Stendarr. Other types can go with Julianos I suppose.
If you think about it, the Baalspawn being trained to hate his own father who was a mage, and honing himself to be particulairly effective in killing him and his ilk, seems rather morbid to me. Of course, a lot of classes didn't make sense if you followed the storyline and the AD&D ruleset, such as Barbarians, Rangers, Druids and to a lesser extent Paladins.

The Father was evil and didn`t care two jots about his Baal children except to suit his own needs. Also, the Player Hero had the choice to not be evil and to fight his Baalspawn heritage and overcome it.

Surely you know this if you played the game.

I consider Gorion the real farther of the Baalspawn. Nurture over nature my friend.
Which is why forgiving Sarevok later on is such an obstical for me.

But of course, you could just ignore Gorion entirely and the game does encourage you to go your own way. However, if you spend 20 years of your life with some bearded dude you called dad, that is something you can't just ignore in my eyes. It also seems unlikely that Gorion would allow you to become particulairly effective in killing (and generally hating) mages. But that's just me.

I think with what you are describing as your preference for your character, I would scrap the prejudice against magic and enchanting. If you are going to use Dawnbreaker which is a great sword for that type of character you will need to refill it which is enchanting and will increase the skill. As far as lore goes, Arkay is 'good',. a divine, and decreed that 'spirit trapping' the energy of dying animals is okay just the same as using a sword is okay as long as you are not back stabbing old ladies in the alley. Apparently the animals' and undead spirits' you 'trap' is just a tangential energy and the Father of the Dead will still move them on to their next stage of entropy and recycling the life chain.

definitely go Lord, as the idea is you want synergy with your innate defenses/skills. Mixing a Breton's magic resistance with the absorption of Atronach is not as good just like Breton Atronachs were a bad idea in oblivion. even if you don't get the alteration perks, there are some items to increase it and the quest as mentioned above. My Breton has 105% MR with above quest.

i think you should consider alteration and restoration as magic - bad thing about illusion and calm/fear is that it is great at low level but you need about 8 perks to use those later in the game. on the alteration tree u can also use paralyze which is a good way to incapacitate something then you can kill them or walk away. and alteration goes up very fast. so basically you get to use shield and paralyze spells by utilizing the same perk progression which is a good thing. i think you should also check out the mage's guild, I think the they will need you, and that is where all the good alteration spells and training are to be had.

To me, a wizard slayer is a mage with one-handed instead of conjuration...

I would play a Paladin like this:
Sword and shield in battle, restoration and alteration for buffs (water walking is totally a divine skill, at least so I'm told).
So this would lead to these skills (Speech, as a Paladin is a man of the people, lock picking (only in dungeons!) and enchanting level on the way):

One-Handed +++
Restoration +++
Block +++
Heavy Armor +++
Light Armor ++
Alteration ++
Speech ++
Lock Picking +
Enchanting ~
(19.5 points)