The adequacy of descriptions and explanations:

If consciousness were just interpretation, then sure, you could have no control over your actions because all you could consciously (i.e. interpretively) do is interpret. That said, isn't interpreting an action? When a reader interprets the metaphor of a poem, is this something other than an action on the readers part? Is an implicit unwrought understanding not an action on the readers part? Perhaps you mean perceiving?

If consciousness were just interpretation (including action or not) then it would be logically impossible to have language. One of the few things which distinguishes us from other animals is how we use language.

As an illustration of the scope of explanations, by one adequate description WWI started with the assassination of an archduke; by another with formal State declarations of war; by another the start goes back to ancient Rome... We simply do not know enough about the causal processes in the brain to adequately explain consciousness with the same molecular precision which we use to describe water as H2O instead of "colorless, tasteless liquid"; and explain features like "delicious" or aspects like "steam" or "ice".

Controlling our surroundings with our thoughts depends some on how the terms "thought" and "control" are used. Don't we all just agree and think that, for example, ink and carbon fibers in a certain configuration are paper money? The status of the "base" material in the certain configuration and its status function are matters of institutional fact (as compared to "brute fact" - per Anscombe), i.e. something we create with language (speech acts).

#Necessity and sufficiency

If a thought is the result of neurons "firing" (as I believe is scientifically proven at this point), then the neuron firing must, by this definition, take place before the appearance of thought itself.

An axiomatic explanation of empirical phenomena begs the question. We know that neurons are involved, but as of yet and even with fMRI there is little to distinguish an unconsciously conscious brain from a consciously conscious one. In addition to neurons firings causing mental activity, it can also be said that intentionalistic focus causes neuron firings.

This to me is the same as saying that the activities that lead to a specific thought will have already taken place before that thought itself is conjured. How can one, in this case, say that the thought was the actual source of anything? Could you address this issue in specific, disregarding the rest?

I may vote for a Presidential candidate because I think that their administrative policies and positions will better suit the country. This is a sufficient cause for me to vote, and, of my voting, but it is not necessary, nor is voting necessarily caused by my thnking such.

Yes, neurons are involved in brain activity but is a thought as you describe? Do you mean "thought" strictly in terms of propositional (linguistic) and sense (visual - why not sound, taste, smell, touch?) content such that may be expressed to any other similarly structured and intentionalistic biological form? Do you mean "thought" to describe all of consciousness or only something like "a proposition with a sense" (pace Wittgenstein)? By "appearance of thought" do you mean consciously conscious consciousness or awareness of awareness? The language we use and how we use it will sometimes lead us astray.

As for physically changing (i.e. exercising a control over) our immediate environment, the motor nervous system can be intentionalistically engaged, for example, to swat a fly without thinking just as the motor nervous system can be engaged to inadvertently jump at a loud bang perceived through the sensory nervous system. There is an explanatory behaviorist/materialist/determinist I/O analogy, but think more about how you breathe consciously at times and yet when you sleep you do not die from oxygen starvation in your brain.