Theorycrafting and Viabilities: Items and Runes

Alright, so, after seeing this video, I seriously think my knowledge of stats, theorycrafting, and the like are all very flawed. I guess it's because I don't have enough wins/games on many champs, or I just have not played many champs enough. However, I guess since he's been playing Katarina a lot, he's had a lot of experience with her that he knows which is good and which isn't.

Right now, I think I'm going to build a runebook for specific champions. Yes, I have 3 pages right now, but in the future, 7 champions + respective runebooks would be awesome.

Jarvan IV (Tanky DPS)
ArP Reds
Flat HP + Flat MP5 Yellows
Flat CDR Blues
Flat HP Quints
Notes: Jarvan is always mana-starved, so just having him with Flat HP would cripple his laning. This could be fixed with a Manamune, but there are so much better items for him, that I believe that a full DPS Jarvan would not need that much mana. I would probably switch my glyphs to MP5/L, especially since his E->Q combo is so versatile.
Base Build: Berserker Greaves | Youmuu's Ghostblade | Frozen Mallet | Black Cleaver | The Bloodthirster | Atma's Impaler

Brand (AOE Caster)
MPen Reds
Flat MP5 Yellows
Flat CDR Blues
Flat AP Quints
Notes: Brand does love MPen, so blues could be switched to MPen. However, he's also combo-dependent, and the faster you can get them off cooldown, the more times you can burst.
Base Build: Sorcerer Shoes | Will of the Ancients | Rabadon's Deathcap | Archangel's Staff | Void Staff | Banshee's Veil

Blitzcrank (Hybrid Damage Soak)
Flat HP Reds
MP5/L Yellows
Flat CDR Blues
Flat HP Quints
Notes: Blitzcrank isn't really a 1v1 ganker, but he sets up ganks nicely. I could even switch quints to movespeed if I plan on roaming with him. His DPS does involve lots of Q and E spamming, so it MP5/L should help.
Base Build: Mercury Treads | Manamune | Banshee's Veil | Frozen Heart | Trinity Force | Guardian Angel

Jax (Hybrid DPS)
MPen Reds
Dodge Yellows
Flat AP Blues
Dodge Quints
Notes: He's probably the champ I'll be spending lots of IP on. He's fun to play, but he's dodge-dependent, so it should make sense to stack them in my runebook. Also, most of his damage is magic, but he does some physical DPS as well.
Base Build: Ninja Tabi | Guinsoo's Rageblade | Rylai's Crystal Scepter | Hextech Gunblade | Lich Bane | Rabadon's Deathcap