You're welcome!
You'll surely find these forums very useful no matter the method you use to learn.
I think the "emotions et al" theory seems to work because they teach in Spanish 102 or 201 how to express what you feel in Spanish. In a nutshell, every attribution to subjunctive comes from a specific step in acquiring Spanish as L2 (language 2), being it that you need to express your feelings, needs, doubts and how likely can things be. Give me the lists of subjects you need to be proficient about in order to communicate and I'll give you back the list of "what is subjunctive" according to that list.
I wonder, where's the emotion and where is not in:
¡Creo que me ama!
and
¡No creo que me ame!
¡Creo que no me ama!
I always repeat that English has a simple grammar, word order is important to comprehension, and it is heavily dependent on semantics, and Spanish has a complicated grammar and is less dependent on semantics and word order. In both of them and every other language grammar is
parsed.
Compare
I expect he is coming soon.
and
Espero que llegue pronto
In English both indicatives are the hint that English considers indicative to cover a wider range of connexions with reality. So word order and semantics relay and as you can expect someone coming but you cannot come someone expecting -or maybe you can, but not with any related meaning- the final meaning is clear. In Spanish indicative represents an action and not the idea of an action, so I expect (action) he is coming soon (thing). Subjunctive takes care of setting that an action is not happening but just the idea of it to happen [and that's a core idea in Lozano's]. The omnipresent "que" with a meaning between "and" and "(nothing)" takes care of telling the brains how to parse the sentence and then get the meaning. In Spanish "Llego que esperes pronto" has no meaning either, but Spanish speakers don't rely on comparing "llego que esperas pronto
" and "espero que llegas pronto
" to set the meaning. We can say "que llegues, espero pronto
" and still get an univocal meaning, because we don't rely exclusively in word order and semantics as "que llegues" continues to be a thing that stands alone.
This takes us to your examples:
Deseo que
llegues temprano esta noche (
noun)
Busco un coche que
tenga un motor grande (
adjective)
Venderé ese coche
cuando vaya a la Argentina (
adverb)
and some counterparts:
Veo que
llegas temprano esta noche (
noun)
Busco un choche que
tiene un motor grande (
adjective)
Me sentía feliz
cuando fui a la Argentina (
adverb)
where the mistaken one ("Cuando vaya a Argentina estoy feliz") -don't worry at all- teach us that natives and foreigners have mistakes, but very different ones, which should teach us something.
My conclusion is that behind the "emotions ....." theory hides a cerebrum that still thinks in English and doesn't welcome thinking in Spanish. I'm not saying it shouldn't be that way in a lot of stages of learning L2, but I'm sure subjunctive
isn't that.