Moving to Portugal from the Caribbean; Help needed!

Pleasant good day all!

My name is Anthony, and I currently live in the Caribbean island of Trinidad and Tobago. My family has been seriously considering a move to Portugal in recent months, however, there is a lack of information for us here. As such, if some kind souls can please point us in the right direction, we would be very appreciative. Here are our questions:

1) We are currently planning on going on a D7 visa, since my father is a retiree, and has some savings in hand. What are some criteria that may lead to one getting rejected for this visa?

2) Can a person be rejected for a residency permit? If so, are there any known conditions to effect that?

3) Regarding SEF, what is the situation with them right now? We’ve heard that some kind of restructuring is supposed to happen, but how will this affect things? We also understand that they are a bit slow-moving; in that case, if a visa expires, and you don’t have your permit yet, what happens? Will you be kicked out of the country?

4) How does one apply for their dependents under this visa? The form we got has no spot for dependents, so if we can get some clarification, that will be great!

I know this is a long post, but we appreciate any and all help that you can give! We are seriously looking at migrating from our country due to a lot of instability, crime and other social issues, however, we would like to be sure that wherever we move, we can move there safely and securely, without worrying about being rejected or removed.

Thanks again, apologies for the long post, and looking forward to the responses!

Respectfully,

Anthony.