Spanish language Q&A Forum

I have had this problem for a while, and no Spanish speaker can readily explain it:

In English, an adjectival form can only describe a noun; for a verb, you must use the adjectival form. The only exception of which I know is "I am well." Because so few English speakers have good grammar these days, "I am good" has become a colloquialism that is acceptable. But one can never say "I cook good" or "He lives happy".

But in Spanish, I see this all the time though Spanish speakers also acknowledge the rule that adverbs, not adjectives, describe verbs. In this lesson, I just saw it again: 

Espero que vivas feliz en tu apartamento nuevo.

Hola a todos

I just found this sentence on Kwiziq:

'He estado de viaje y me ha encantado todo'

So, with de I guess roughly this means 'I have been doing travelling'

But please can someone explain...

1) The differences between using 'he estado de viajar' vs 'he estado viajando'?

2) And can we use 'he estado de +infinitive' with all verbs?

Saludos

When you are talking to a young person and mention another person who is older (and vice versa, speaking to an older person and mention a younger person), but refer to the people as you, which verb choice should you use, vosotros or ustedes?  

Examples: 

John (older person) and you (child) are going to the store tomorrow. How to translate You (both) are going to the store tomorrow (speaking to a child when the older person is not present)?

You (older person) and Maria (child) are going to the store tomorrow. How to translate You (both) are going to the store tomorrow (speaking to the older person when the child is not present)? 

Also, does it matter which form is used (vosotros or ustedes) whether or not both people are present (both older person and child)?