As regards the structure, that is no problem at all with Kirby, so that is both a yes for your first and second questions. Instead of having a flat issue structure, it might make sense to put the issues into year folders, as the Panel will slow down if the number of subpages becomes too big. With currently 25 issues, that is no problem, but it might be in the future.
You can either create your authors as (Panel) users or set a separate page with subpages for each user, which you can then link to each project. Of course, you can also use other relations like categories, tags etc.
As regards the content, big sites like that have been built with Kirby, e.g. http://nimbus-lighting.com/, built by @bastianallgeier himself. You might like to check out this post on performance.
Kirby has a thumbs class for generating responsive images in your templates. There’s also a commercial plugin available which can generate thumbs on the fly.
If you use the search function in this forum with keyword “performance” you will find more post on that issue.