1. Your point on the vampire is kind of an oversimplification of what's actually going on. It's not as if you somehow gain mana when your opponent controls your creatures, you still payed 16 for your vampire, and it's still significantly worse round after round with PB on it. You could say the same thing for many creatures affected by a control card, true, but it's more the fact that your opponent doesn't really need a variety of spells to deal with what you're doing between the Angel and the Vampire.
The vampire's base stats are decent for 16, but comparatively, other creatures at that cost have better.
Overall, all I am saying is that I don't think it's a good idea to go into a game consistantly casting creatures that require only one line of interaction (Finite Life). If it's working for you, that's fine; do what works if it wins you games. The Vampire and GA are certainly strong enough creatures to support what you're trying to do. I'd just advocate being a little more flexible in your openings, and to consider a combination of creatures that require your opponent to interact on different axes in an effort to round out the build.
2. I'm kind of skeptical that you only need a Vampire to attack. At least in my games, even a Pet Steelclaw or Adramelech needs some kind of additional creature support in order to effectively go on the offensive against a group of large creatures plus the enemy Mage. I don't really know what kind of builds you play against, so I can't say for sure though.
The only one posted here is a "pre CoK" FM sniper build, which is pretty odd honestly. Pre CoK I would say that Grimson is an awful card, but with the new line of intercept creatures, he has become significantly better since it's much harder to just efficiently nuke him down with a Fireball/Hurl Boulder.
3. Well, here's my opinion on the "very important" cards, with a "yes" for it should be included in every book and a "no" for it's not that important:
Dispel: yes.
Seeking Dispel: no.
Teleport: no.
Nullify: no.
Jinx: no.
E. T.: no.
The only card I've found I can't live without is Dispel, because enchantments are just too important. The rest on your list I obviously have very different thoughts than you about, but they're all just meta-pick cards that no book needs from the start.
There are many more cards from other schools that I could list that are strictly more relevant than 95% of the cards you list there. Rhino Hide, Bear Strength, Bull Endurance, Regrowth, Cheetah Speed, Agony, Ghoul Rot, Marked for Death, Chains of Agony, various heal/protection spells from the Holy school, a few from the Mind school like the Push spells and Block...those are all cards that don't need a really specific situation to be good. Cards like Purge Magic, Mage Wand, and Elemental Cloak aren't inherently worth their cost and are not worth playing unless youre in a very specific situation. Dispel is really the only Arcane card that I can guarantee I'll use every game, or at least have a very high chance of using.
4. I could say a lot here, but I'll suffice with this: flying on these intercept creatures isn't terribly relevant, because creatures lose flying when they guard, which they should be doing because they aren't good at attacking. The angel especially only actually heals when it chooses to forgo its flying and guard, so I don't get the correlation you're making. I've played against these cards, and really, you don't need to explain it out on paper to get a good idea that they're pretty much all the same card, albeit tweaked in fairly irrelevant ways.
TLDR: There's a lot here we disagree about, but my main on-topic thought is that I'm going to respectfully recommend that you try to include some creatures that require different answers into your opening, as a way to be less predictable and cover the weaknesses of your creatures. Right now, they share the same weaknesses, and my own experience has told me that it doesn't take long for your opponents to adapt to that and punish it.
Not saying your opening is really weak, because I did the math and you seem to be optimizing the amount of mana you're spending (which is good), just that adding some variety in the types of creatures you play would make your opening harder to attack.
First, im really surprised that you dont see nullify, teleport and jinx as necessary metas. You might have a much different meta game than I faced yet, so I would be curious how a game against you develops. IMO those three cards allow some really nice actions with immense effects on the board (e.g. teleport can allow your creatures to attack the opponent mage with 10+ dices or prevent 10+ from your mage in situations in which this were not possible otherwise).
I see your point that both, the angel and the vamp, have the same weakness (i.e finite life) and that in some situations its better to just have a creature with higher base stats (damage dice, life, armor, maybe piercing). Therefore I will try different openings that focus on creatures that have better base stats and see how they perform compared to the angel vamp combo.
So for now, I will try a grizzly+gorgon archer combo while building up channeling. The idea is that the increased channeling and the gorgon archer forces the opponent to attack while the grizzly makes sure the opponent get hits hard if he moves into the grizzlys/archers zone.
So here is the opening I thought of:
Round 1 (20 mana):
Grizzly+harmonize (face down), total cost 19 mana
Round 2 (11 mana):
arcane ring + mana crystal, total cost 6 mana
round 3:
before channeling phace reveal harmonize (will get benefit of the ring since its a new round, costs 3 mana). Therefore, this round I start with 14 mana.
Play 2 face down enchantments on bear or whatever.
Round 4:
Gorgon archer+mana crystal if opponent is slow or something defensive if he is quick
The downside of this opening compared to the angel opening is that I have no interceptor, which really helps against some kinds of rushes. On the other hand, I guess the grizzly will do quite some nice damage to the opponent while he is focusing me and I will build up defences quickly and use voltaric shield often if he is rushing. Have to see how it turns out in a real game.