If the text on the Adv. Port says no march for 24 hours and the text on the Pioneer Express Port says it is a "special" Adv. port, and then lists some of its features, you should assume it is exactly the same as an Adv. Port except from the differences listed.

I have been through server merges and have yet to hear people moan that they misunderstood the meaning of something, as if that's Evonys fault.

As for your army size, that is your problem to deal with. You should have taken your notice period before the merge to stock up enough food. Also, when they say the the no upkeep will last for 3 days, both merges i have been in before the no upkeep lasted closer to 2 weeks. Don't assume it will be the same again, but at least be a little optimistic.

Despite this, i do feel that there is no need to have the 24hour cooldown on the pioneer port. The cooldown was put on the Adv. port to stop people porting next to others and attacking immediately. This cannot happen after a server merge as people have the option to stay in truce, if they opt to come out of truce that is their fault.