The specialty dining BOGO is an on-board perk. To get a certain time slot you could book for one pre-cruise and then modify things onboard, but you might get charged the on-board price for one. Also, the perk is for first and second night, though again on board on certain ships, you might be able to book other nights.
Lobster being served on the second formal night is mostly a US departure thing. In other markets it has been hit or miss whether they offer it. Ovation doesn’t look like it offers it either while in Australia.
Biker, who is waiting for the folks to weigh in with the exceptions.
Not if you book double and the second person is a no show as the OP plans to do. That went away about 3 years ago. A few folks may have gotten the points, but officially that is not supposed to happen anymore. To get the double points you have to book solo.
That restriction might be avoidable by calling or using a TA (like the cheaper GTY rate might not come up if you search solo but it might bookable by calling), and you can also book solo and get the double points.
That varies and, on some sailings, the NRD is still cheaper. Though, you have to take into account the overall cost, like the NRD may be cheaper but you can't apply your balcony discount to it like you can on a group rate.
I said it was convenient, not that it's easier nor more hygienic as some worry about that too apparently. Like at other venues, you'll likely want to use a cup to pour the water into the water bottle.
Don't book on deck 13 either then - while categorized as unobstructed, you may not like the support beams in the way on some of those balconies (nor the large overhang above).
Many/most ship location sites/apps use only land-based AIS receivers to report ship location. Once out of range, those sites/apps freeze like that, and you have to look at the last timestamp of the data to realize it's "frozen". Cruisemapper adds sat locating data to the mix and is much more accurate when the ship is out of AIS range.