The new Allagan set of items needs to have a small customization option.

[NeoAmon]

You have to clear T5 to run T6, every single week.

News to my eyes. As far as I know you only need to clear T1-T5 once to complete the current quest and then be able to get the new one in 2.2.

So yeah, source please? I don't think SE would go as far as making sure T5 is a gate to T6.

As for 4900 HP, will it is your play style, more power to you. However, you only need 3900 HP as a caster without group buff or food to 7 man Twin.

except in the domain of bragging rights

Not really, it is because main stat makes Allagan 2 superior to crafted gear no matter what you meld. There is no amount of melding you can do that can cover the lose of 6+ main stat points per piece. That is why players want it.