So if you book a room only discount, you can absolutely add park tickets and/or dining (and you can add one or the other). It will become a "package" then and be subject to package booking rules I believe (i.e. $200 deposit, full payment due futher in advance).
However, if you're booking room only and feel that buying tickets separately is a better option (i.e.
Undercover Tourist) then you can do that too. And also, if you don't think dining plan is a good option for you guys then you don't have to add that and you can pay for meals OOP (out of pocket). In that scenario then you would have a room-only reservation subject to those rules (one night deposit, full payment due much later).
Typically when Disney releases these deals there a ton of options between the public offer, the visa offer, the room only, the SPD (stay play dine) so it's probably best to keep an open mind and see what's out there before you set yourself to anything specific. Availability and prices will vary between all the different options - it truly is a little confusing at first but you'll probably find exactly what you want if you look hard enough!