Geo Search Tool to finding videos by location

I translated this text as a translator, I apologize for the errors.
I create a website Videomapia. This is a geo-search of videos. For the search is used GPS. Therefore, the accuracy of the search is very high.
On the first page of the site there is a map on which the red lines show the places where the video was filmed. To search for videos, left-click on the map where the red lines are. Previews of found videos appear on the left. There are also links to watching videos.
When watching a video, the mark on the map shows the location of the shot. The label moves synchronously with the video. You can rewind the video and the label itself will move to a new location. You can also click on the track on the map and the video is rewound to this place.
Videos hosted on YouTube. The site is a bit like google street view. Only interesting video to watch. It moves and there is a natural sound. Videos are added by users in various places. Often in these places there are no photos of Google Street View.
Please add tracks to your videos. It’s easy and free (crowdsourcing). More views of your video, the video can be used to create or check the maps. I can help you add your tracks.
Please repost information about this site to your friends.
Link to the site.

Is it licensing compatible to use arbitrary youtube video to help create OSM map?

Just like the photos (and others). Permission required by the owner of the video.

I will have two questions if you do not mind:

a) Did you use any library other than OpenStreetMaps on this project like a framework or anything else? Or did you code the whole thing from ground up?
b) In total, how much time did you need to attribute to this project to finish it? Would you be able to show me the ropes if I get stuck somewhere, especially in terms of OpenStreetMap integration?

I’m asking because I recently finished a web development course and I am trying to further develop my skills by creating small projects that I’m interested on so that I wouldn’t get easily frustrated and bored. Thus, I want to create something similar to your project but instead of videos, I want it to fetch the data from different websites so that people could see all the available apartments for rental and buying options. For example, if someone is looking to buy an apartment in Spain, they would be able to just go there on the map and see the possibilities through data aggregated from different sources like this, and if they zoom in, they would be able to see specific cities and more options. I actually saw a concrete example for what I’d like to accomplish but it was only for rentals and limited to Ukraine on a page called LUN.

You are a little mistaken in the names. I do not use OCM library (this library does not exist). OSM data is used to create a map tiles. I show the map tiles using a library leaflet.
I also use these scripts to calculate distances and directions. I also use Bootstrap and jquery to display the site.

I do not record time. This is a lot of hobbies. I guess it will be a few months with daily work.
Much more time was taken by the promotion (advertising).

I do not use integration with OSM (I show only map tiles - this is not integration). Maybe you get help from other members of the community.