1. I prefer jasna over Lada. I think in my opinion it depends on your settings on jasna. If you don't using Secondary Restoration, such as Topaz Video AI, RTX Resolution or else it is could be faster. But again, it depends on your settings. Since for me, the reason i am using Jasna is because there is so many tweaking i could try on with. And experimenting with it. But, if you want simple use, and fast too, you could go with Lada.
2. As far as i go, i am render max 3 videos (2hrs Estimated per video). And i am too afraid to overuse the graphic card, since i have bad experience with fried graphic cards :

3. I mean, if you okay with it just go for it. My suggestion is if you want to after quality decensoring. Because the final results are depends on your source file. For example, if you are downloading the video with low bitrate and quality, and you decensoring it, i think it would be messed up. But some people are okay with it and i couldn't against it. Again, it is how you want to enjoying it.