Well, if you're worried about the integrity of the files then there's hashing performed for files downloaded, first time file is downloaded the hash is saved so it could be checked later. Hashing algorithm is pretty weak but better than nothing.
I guess if you'd want 100% security you cannot be sure because of course, executables can be modified, corrupted so yeah... It's not much safer than torrents in this regard.
If you ask my opinion on launcher vs non-launcher for read only app I think having standalone app is simpler, people don't need to create accounts, they can just download one zip and off they go.