Does these custom made warehouses have use in game and also does the game look that smooth when playing as in no jaggies
Yes, so you need to download a mod called RICO (Ploppable RICO is the correct name) but generally just known as RICO. Anyway, you can then download assets from the workshop (such as these warehouses) that you can just plop down, like a park, or other building you could just plop down. But these ones count as industry and do provide jobs.
You can also configure RICO quite a bit, so alter the number of jobs each building creates, and you can also set it up with all the vanilla buildings, including the growable ones, so you can just "plop" down any building without having to zone it first, and you can donwload loads not just industry, some of the commercial assets are really great, as I feel the vanilla ones, the low density commercials and generic industry, are horrible.
Secondly I then use Move It! mod to merge buildings in to one another, the warehouse on the top right is actually 2 clipped in to each other. You need to play around with it, the above is a simple example, but there is actually a lot you can do by clipping buildings in to each other to create your own designs in to your map - it also means you can move the building away from from being right next to the road, and believe it or not the building will still operate including even the little cars or trucks etc interacting with the building as normal, they will drive over whatever you have between the normal road access point and the building interaction point.
The roads look like that becuase I use another mod to change the colour and road markings, called Roads united Core+, with the North America PLUS theme.
Finally, the textures on the concrete are partly a combination of custom map theme (Arrowhead Junction - which by the way, I highly recommend watching that series on youtube) and then ploppable decals on top.
You do need to absolutely mod the living crap out of the game to get it to do what I have done in some of these screenshots, IMO it's well worth it, although you have to be a little careful with which mods you use as there is a risk it can break your game, you gotta think about which ones could possibly conflict with each other, that is where you will run in to problems.