What does this mean?

If you're implying that something romantic may be evident, I would look for way more evidence than just that. Otherwise, I would just feel honored to be considered that important to someone. 

You can be important to someone without them considering you family or having a crush if that's what you mean. If you think they mean either of those things have a look at other evidence as well.

Means you are good to your friend, and trusts you and would love ro have you in their life forever.

It is positive . It means that your friend wants you to be around and spend time together. You friend means that your opinions and what you say matters and that your friendship is valuable . In other words your friend wants you to sta6 and not to leave . https://www.jw.org/en/bible-teachings/teenagers/as...

It means that you are an important part of their network of supporters.  You may be supporting them by encouraging them with words, by giving them money, by giving them advice, or providing emotional support.  They likely see you as a pawn in their plans for reaching their goals, whatever they are.  They don't want to lose your friendship, because you have resources that they want to use.  They may be sincere or not about how attached they are to you, so "important" could mean they want a closer, honest and sincere, mutually trusting relationship.  But they could also just be superficial and feeding you the words they think you want to hear to keep you around and supporting them, even if it is at your personal expense.

It means you're important to them. 

important - adj.

1. of much or great significance or consequence:

2. mattering much (usually followed by to)

3. entitled to more than ordinary consideration or notice

4. of considerable influence or authority, as a person

5. having social position or distinction, as a person