General recommendation for requests is to call the resort no earlier than 2 weeks before checkin (The local resort doesn't have your reservation in their system before then). It also doesn't hurt to mention your request again when you check in.
As for it being guaranteed.... It's most likely not going to happen. The only ways a specific room can be requested/guaranteed are with certain presidential reserve units which can be specified/guaranteed at the time of reservation, And Wyndham Owners with certain levels of VIP can 'request' a specific room which is usually honored. With the 2nd method, There were some reports at one time that Bonnet Creek however didn't normally honor those requests, which caused some VIP owners to complain..... And I also don't know if that VIP perk still exists or if it is one that has been discontinued. Either way, VIP owner perks are not transferable, which means that if you are renting you can't take advantage of it, even if renting from a VIP member.
It really depends upon your definition of Value. For the space and proximity in the units, you'll likely still pay less than something comparable onsite. You however likely won't get the same nightly rate as you could get on a longer stay since Wyndham charges a flat fee to owners for a 'guest certificate' which is required to put the reservation in your name. Other than some of the highest VIP level owners which receive unlimited free guest confirmations, everyone else is required to pay this surcharge which they then include in the price you are quoted. Normally it's cost is spread out across the entire stay, which means for a 3night stay it's going to impact your nightly rate more than it would on a 7 night stay.
Lake and Fireworks view, You would need to be in one of the older 3 towers. Personally I'm thinking Tower 2 might be your best bet since it's not going to have Tower 4 block it's view as much as Tower 3 would, and I think Tower 1 may be angled enough that one of it's wings could be facing the wrong way for a great view.
Either way, You'll likely want a higher floor since Tower 4 across the lake will impact your view slightly.
Tower 6's higher floors are exclusively Presidential units. also, one of the wings is angled enough that it would prevent really good views of the fireworks.
Personally i tend to prefer the
Walmart for my shopping, But i'm also usually just getting items like Alcohol, Soda, and MAYBE some small snack food type things. The Liquor store located at the front of the Walmart just makes it a convenient all-in-one stop for me. For my needs, the Walmart is quick, easy, and not that complicated....however i'm also not looking for fancy items or things with a large price variance between stores.
There is a Publix also nearby that as a more traditional grocery store might have a better selection. it's just down the street a little further than the Walmart. I haven't been there in years however so I can't give you much information on it.
There is indeed a more full-service Coffee/pastry shop with Starbucks located in the Hotel Lobby. I'd agree that it likely would be a better destination for your dad's morning walk/coffee stop. Sorry I can't give you the opening times....I'm not normally an early riser on vacation.
Two Bedroom Presidentials are all going to be located in Tower 6, which coincidentally is next door to the Hotel, shares the parking garage, and is connected to the hotel via an enclosed walkway. I've heard mention that all 2bdrm Presidentials are "conservation view", meaning the parking lot/DTD side of the building.... but I'm honestly not familiar enough with the building layout to know firsthand.
Either way, Because of Tower 6's location and orientation on the property, only 1 wing of the building is capable of firework views. I've heard however that there is a lounge for presidential guests in that building that can be used to watch the fireworks. It might be worth asking about when you check in.