If you fly to either airport 1:00pm is cutting it too close in my opinion. Ecstasy has a 4:00pm departure time so check-in will be 1:00 to 3:00pm. Check for flights well before noon to be safe. If you fly into HOU Carnival doesn't offer transfers, if IAH they do but they are pricey. If doing HOU (Hobby) you can check with www.galvestonlimousineservice.com
they have transfers from either airport and are, I believe lower cost than the cruiseline.
On Ecstasy be careful of cabin selection, staterooms V23, V25, V27, V34, V38 and V42 have partially obstructed views. I checked on the bath/shower question but am perplexed. The diagram shows a tub but the description says shower.
Happy sailing, Neil