Translation:I am always at home after five.
No way, always Estoy for this sentese, you are in a place, Estás en un lugar, and the second one you can not add "a" between de - las.
Estoy also can refer to how do you feel, estoy contento, estoy triste, estoy nervioso, etc.
Soy refer to, in most of the cases, how do you look like or act normally, soy alto, soy flaco or soy alegre, soy simpático, etc. GL ;)
Isn't cinco masculine? and singular? From what I understand numbers take on the form of the noun it is accompanying. OK, so in this case I get the feminine use of "cinco". But why "las". Why not just "la"? There is nothing else in this sentence that is plural. EDIT, It appears as though you do consistently use "las" but I would just like to find out why.
Numbers used as nouns are generally masculine and singular, yes. But the number is not used as a noun here.
The full phrase for expressing clock times in Spanish is "las [número] horas", so there's the plural-feminine part. Horas gets left out most of the time, but the article stays. Also note that "one o'clock" is "la una (hora)".
- I eat lunch at one o'clock. - Almuerzo a la una.
It is not the normal colloquial word order to put the "adverb of frequency" before the verb "to be," but occasionally very experienced writers do it in order to be dramatic. Like you, I would advise most writers not to do it, but it is not grammatically incorrect per se. Also, most native speakers will look at you oddly if you say "I always am at home after five."