1) Hyatt web issues are notorious. Prepare yourself for same.
2) G Bonuses can be added at any time, even post stay.
3) Hotel hopping ='s more bonuses. Always.
4) Different promo's are unveiled at different times. I book locations/rooms far out, then check regularly to see if the rate drops, bonuses are added, etc; changing if appropriate. And although it probably won't happen in MCO, I have actually found FS Hyatt's cheaper than HP's at the last minute.
5) I never book a pre-paid. Ever. At Hyatt or anywhere else. Especially at HP. IMO, the savings aren't worth the possible loss if rates go down, your plans change, or the million other things that can happen. I won't risk it. YMMV.

1-4 are standard; others may reply differently on #5.

Enjoy Hyatt and welcome to the forum.