Having played through the Slumbering Tsar I can tell you it is not a cake walk and if your GM believes that you have walked through AP's before this will be the exception. This is a player killer and I believe that a 20 point buy is too low.
Personally I feel you are falling into the trap of building a 20th level character from scratch without even playing. If I were you I would focus more on the first 5 levels and decide where you want to take them as you play. I understand you want to play a switch hitter and I say go for it but part of the reason you play a switch hitter is to have versatility which you are only taking away if you decide right now what your character will look like at level 20.
I think people are slowing down is because post speeds for this group is slow, if we can all agree to kick it up perhaps the game will become far more lively.
I am sorry holiday visits have prevented me from being able to get a post on my characters actions. Minerva will not chase as I think it will be impossible to catch them. I will get a post out tomorrow. Happy Holidays
The feat dampen presence would do wonders for you bypassing some of the common senses. Boots of the soft step prevent tremorsense but only if you move very slowly. Conceal Scent the feat could be taken to avoid the scent ability to an extent, (No Pinpoint).
Exactly what Almonihah said, a lot of this will be working the specifics out with your GM. Leadership is one of the loosest feats in the book that doesn't explain much. The reason I suggested templates is I feel they work better with monsters than adding pc level however that is very subject to GM approval. He is right, they gain exp like a normal pc but remain at one below the level up requirement until you gain another level as they always have to remain 2 below you.
If you have any other questions I am always free to help.
York you are correct, you can't make full attacks however you can spell combat as a full round action so still extremely useful there.
Griffon has an effective cohort level of 8, so you would need a leadership score of 12 and be level ten. At level 11 and a leadership score of 13 it would go up a theoretical level allowing you to increase it as a character level or template if allowed by your gm.
Handle animal while not needed could be useful to teach some of the more obscure but useful tricks.
Ok I wil try to wander all of your questions the way I see it.
I think your build is good except I agree that intensify spell should not be your level 5 feat. At level 5 it does you no good and at level 6 would add only 1d6 to the damage. I would wait to pick it up in your 7 level slot. In place of that feat I would suggest the lunge or toughness feat. The benefit of lunge is for a cost of -2 to AC you can in most situations spell combat without casting defensively which is huge. Toughness is also strong as a d8 class in melee HP never hurts.
If you plan on using your gryphon having it as a mount could be a good idea. You could have it be your movement to gain full attacks/spell combats on people. Leadership could be interesting however if you plan on taking the leadership feat there are honestly far better mounts out there than the griffon but the way I would play it is as the leadership score goes up the griffon would either gain templates or class levels.
Habibo is correct in that you should instead get a ring of protection. A ring of protection offers a deflection bonus which applies to all three armor types, whereas a natural armor bonus only applies to AC and Flatfooted. The deflection bonus is clearly superior for the same price.
I see nothing wrong with the item creation feat and in a long campaign it will pay for itself many times over.
A black blade does not have to be black, in one campaign I have a keens black blade magus that has re skinned his blade as a lightsaber. Go nuts with it, the blade is a flavor dream for the blade bound magus and you should build it however you want.
If you know that you will be gaining a mount in the future it is probably wise to at least put a few ranks into ride. You can use it as a mount and a combat partner honestly, it is always nice to have a way to travel and they are decent combatants but take care as they are very fragile.
I was looking at the achievement feats in the players guide, one such is about killings gnolls. It's called all gnolls must die and you have to deliver 20 killing blows.
Ok so Minerva will definitely begin pursuing the gnoll killer achievement.
GM background skills is a system in pathfinder that splits all skills into either adventuring skills or background skills. With this system you spend your normal skills as always however you wish, in addition to those skills you get two background skill ranks every level but they have to go into background skills. This allows characters to spend a few skill points into skills like profession or craft that normally would never happen due to the games focus on adventure critical skills. I a, strongly for including this system and gaining those background skills because it helps flesh out characters. Any other players have a vote please let me know.
Does anyone have any suggestions on what some good combos would be. I feel like cross blooded Arcane and Draconic with the Admixture school would make a very powerful blaster with lots of versatility albeit behind a bit on the spell progression? Any thoughts
Your feats are fine although you should make sure you take magical lineage (shocking grasp). Honestly your stats are fine, the only suggestion I might make is if you are doing a dex focused build then perhaps switching your 16 in strength to wisdom would make sense. That would give you a better will save and increase a few very important skills such as perception. Your feat selection is perfectly fine and I would not change it. Good luck :)