Header video in mobile and portfolio light box image change

Hi,
I have couple of questions:

1) When embedding a video, like in here:

I can all the info (share button, video name) from the hosting provider (i.e YouTube, Vimeo…).
Is there a way to show the video with a custom player, as if it self hosted but the stream coming from the video hosting?

2) The Video section does not work well in mobile – it won’t play and sometimes it’s possible to see some of the controls – how can it be solved?

3) Portfolio:

I am using this exact page from the demo:

If you click an image, the laptop for example, a lightbox open and then it’s possible to navigate all the other images in page.

I want the same structure of this page – with equal height columns and images, but when I click an image the full version will be shown –
meaning that if an image is 100 x 1000 it will be show when clicking, but not on the page.
The behavior today is that the size selected for the image its the size that will be shown.

How can I fix that?

Thank you