Nice post. Concise, easy to understand.

The true count IS the measure of the advantage regardless of the penetration. Remember, true count is calculated by using the running count and ADJUSTING by the number of decks (or partial decks) remaining thereby adjusting for penetration. There is more slight value to depth of penetration but for now I suggest you ignore as it will be inconsequential.

Your 1-2 spread is impotent in either a 6 or 8 deck game. Think in terms of 1-12 or higher.

When and how to do one or two hands is a raging debate. My general advice is 2 hands if you can play both at table minimum. Many will advise spreading at positive counts. Two hands will allow you to bet more money and raise your EV while at the nearly same variance. At your bankroll, I would counsel one hand until bank is much larger.

Invest in the book Blackjack Attack V3, by Don Schlesinger, as it contains the accurate answers to many, many questions. Read it and then you will use it for reference the remainder of your blackjack life.