Video and Tabbed archived content

Hey guys, I am in the process of rebuilding my church’s website. This theme is really great, the only hold up I have is two things:

1. We livestream our services, and while creating a landing page with the embedded player is simple, I would like to sort of replicate what we use to hide that page until it is used. Basically, at the top of our website is a countdown until the next service, which we have to input every time, and once the countdown ends, a “We’re Live” button appears instead, and it takes the viewer to our player page to watch live. What I would like to do, is NOT have the countdown (although the option to have it would be nice too), and have a popup button, or modal somewhere on the screen that says “We’re Live” or whatever I want it to say, takes them to the page, BUT I have to be able to set when that appears, and when it disappears.

2. I am trying to replicate our archive page, which you can currently see at the link in the private box (if i did that right haha!). Basically it is an image with a rollover of “Sermon” if there is only 1 video in it, or “Sermon Series” if there is more than one. That part I pretty much have down… The thing I would LOVE to do is replicate another church’s archive page, which I will link below. It has the same general layout, except:
After clicking on the sermon’s image and ending up at the landing page, there is an embedded player at the top, with a series description below, and then tabs below that, the tabs are labeled which each part, and upon clicking the tab, there is a description AND a “Watch” button. When you click the “Watch” button, it loads the video into the embedded player up top, without reloading the page or anything… It just switches the video. You can go through the tabs and click the different watch buttons, and it just switches the video without the page switching around or anything.
How can I do that?