It seems to me that the difference between the imperfective and perfective future tense of verbs is that the imperfective refers to a general or uncompleted action; while the perfective refers to a completed action. Though I have also read that the perfective refers to the result of the action. But as far as I can tell it always refers to an action that will be completed, or is intended to be completed.
Я буду есть сыр. - I will be eating cheese (no reference to completing this action)
Я съем сыр. - I will eat cheese (suggesting the act of eating will be completed)
Я буду мочь ходить. - I will be able to walk. (a general statement, e.g. you are injured and can't walk; someone asks you if you will be able to walk and you answer as so, stating - yes, you will be able to walk again)
Я смогу ходить. - I will be able to walk. (suggesting a walk can be completed, e.g. you are very tired, resting on a walk and asked if you can complete it, you answer so, stating that - yes, you will be able to complete the walk)
Я буду смотреть документальный фильм. - I will be watching a documentary (general, no reference to if you intend to watch all of it)
Я посмотрю документальный фильм. - I will watch a documentary (to the end).
Я буду играть в футбол за Армению. - I will be playing football for Armenia. (in the future I will play football matches for the Armenian national team)
Я сыграю футбольный матч за сборную Армении. - I will play in a football match for Armenia. (I will play one game, to completion, for the Armenian football team)
Are my assumptions correct?