You'd rather use "complete" for something that is sort of "fulfilled" (like in many songs, you know, "Oh you make me feel complete!"), which can also be about elements that have meaning one by one but mean even more all together (e.g. a DVD collection, the "complete" series).
You could also use that to convey the idea of "total" more in a figurative way: it's a "complete" disaster, for instance.
You'd say "d'un coup", "en une fois", or "en une bouchée" which is typically used for things you eat... or put in your mouth (mental images, welcome!).
Just like that, I can't think of an adjective like "entier" or something that would mean "in one bite"; you'd just use a phrase or expression like in English (or using slang, but that's a bit early at this stage).
Liaison between the verb and a following word is forbidden. http://www.lepointdufle.net/ressources_fle/liaisons_obligatoires_liaisons_interdites.htm#.U7tdC_k7tJl