1. Blizzard is made redundant by Ice Beam, which is somewhat more efficient. I would suggest removing Mind Reader, but if you bother to teach it Sheer Cold at level 85 you might want to maintain it.
2. A Charge on Zapdos only benefits Electric-type moves, and since Thunder's base power is 120 its outcome figure 84 it may not be necessary. And at level 62 I highly doubt that Return will be very effective; either that or your game processes mutualities very quickly. In short, you should institute something sensible like Rain Dance, which enables Thunder to invariably hit.
3. As a travel assistant Slowbro isn't bad, but in battle overloading Hidden Machines is, more often than not, more of a detriment than a benefit. Surf and Psychic are acceptable, but even though Rock Smash is a Fighting-type move and can ward off Dark guys a Mewtwo with a Brick Break can bring home more bacon, so you should ditch the two other dodoes and teach Shadow Ball and Reflect.
4. Evolve the Larvitar. Now. Hyper Beam has to charge after a successful hit, and its accuracy is 90. When you factor all of the conditions, the standard outcome figure comes out thus:
Base Power: 150
Accuracy: 90
Math: 150 × 0.9 (reciprocal of 90) ÷ 2 (for recharge) = 67.5.
Strength is more powerful than that. And the same goes for Blast Burn: As a hard-to-acquire move, Blast Burn induces the misconception that it should be taught. How wrong you would be; it functions exactly like Hyper Beam. Avoid using these moves except as a last resort.
5. Fire Blast may have a higher outcome figure than Flamethrower, but since there are only five Power Points (compared to Flamethrower's 15) levying possibilities, keep Flamethrower instead.