Fictional

Thank you much, works like a charm!

Yes, but you need to know what the tags are, which makes things a bit challenging. {member_name} doesn't mean anything in this software, which is why it's not working for you. 
If you want to display a member's name, then you need:
{expression="\IPS\Member::loggedIn()->name"} or its shorthand version:
{expression="member.name"} I'm afraid I don't know where you can find a list of these expressions. My technique is to look for similar expressions in the templates and then experiment.

Is it possible or is there another way to use tags on .Pages pages?

For example, rather than saying Welcome back! on my home page, I'd like it to say Welcome back Fictional, I tried using {member_name} and that didn't work! There's also a few other things I'd like to Display (such as unread message count, last visit, and show latest threads by name, category posted, date posted and author, not sure if that's already a feature) my page is written in HTML Via Pages.
 
Thank you for taking the time to read!