I would dump the Alteration perks:
1. A significant number of the Alteration spells are pointless if you're going to cap out physical damage resistance with armor and armor skill and perks and none of the other Alteration spells are necessary for a canon build.
2. Magic Resistance perks are also a waste because with your Enchanting build you can cap that by getting the Agent of Mara power and stacking the unique Magic Resistance enchantment you can learn by disenchanting the Shield of Solitude with the generic Magic Resistance enchantment on your shield and then making one of the enchantments on your necklace or ring a Magic Resistance enchantment of either kind (the cap is 85%)
Taking 2 of those perks and putting them into Deadly Bash and Disarming Bash would yield better results. If you aren't playing on a PC you may want to reconsider the Shield Charge perk. While it's a decent perk power, it's been known to glitch out so that it doesn't work anymore and can only be fixed through console commands. If you spare that point and take the remaining 6 perks you put into Alteration you can do a full basic Alchemy build. This will give you the ability to temper steel weapons, which have a clean simple look to them befitting of a paladin, to do as much damage as you'll ever need in the game on Maximum difficulty settings.
There's lots of ways to stack up Magic resistance. If you use the Shield of Solitude, and Magic Resistance from another disenchant (radiant item, one shows up eventually) you can double enchant items with both effects. That helps a lot.
As for Mage Armor, it's counted separate from Physical Armor, so saying you've gotten to the cap, that's 80%, then cast Dragonhide, that's another 80%, which makes you nearly invulnerable to physical damage. (About 98%) With just dual cast Ebonyflesh, and Stability, you get about 90%. Likewise, Spell Absorbtion layers with Magical, and Elemental resistance. So, you can get up to 80% SA with the Atronach Stone, and perk, 20% of spells will get through (the others will be absorbed to refuel your Magicka) then 85% MR, and (let's say) Shock resistance reduces that to about 7% actually doing damage. Of course, this nigh invulnerability tends to make the game boring, with little hope of anything killing you, but that leaves you free to stay with 100 Health (or 130 with the Gauldur Amulet) and all your level points can go to Magicka/Stamina. Really depends if you're going for an unstoppable min/maxed build, or not.
You can also Enchant up to 100% Magic Resistance, but it all has to be on 1 item, and requires a Crafting Loop to pull it off.