Frigate 5 required for T2 Cruisers?

No, definately not. A character could have racial Cruiser trained to 5 (and the associated Adv Cruiser skill such as Logistics) trained and fly the T2 cruiser without taking any racial frig skill to 5. In regards to the response about needing Assault Ships to train HAC, this is true, but you don't need a racial frig skill to train up Assault Ships (though you obviously would to fly one).

In order to fly t2 cruisers (at least that I checked) you only need racial frigate to IV. However, in the case of Heavy Assault Ships for instance, you need Assault Ships to IV, and you cannot train Assault Ships without having a racial frigate at V if I am not mistaken. In the event you already have the Heavy Assault Ships skill trained and are a Caldari pilot, you could gain access to a secondary Racial HAC with only that race's frigate skill trained to IV. I believe this is also the case for HICs (interceptor/interdictor extension) and Recons (Covert Ops Frigate extension) but not the case for Logistics ships.