If you want to convert your blu ray to mkv, you will lose menus. You can keep subtitles and extra audio tracks however.
Since you don’t want any compression, the tool to use for this is MakeMKV. It is free while in beta, though you have to go to their website each month and download a new beta key. It has been in beta status for years now, with no end in sight. Here is the page with the beta keys: http://www.makemkv.com/forum2/viewtopic.php?f=5&t=1053
MakeMKV will decrypt and rip the blu ray for you into an mkv file. It won’t re-encode anything, and so the output mkv file will be very close to the size of the original blu ray main movie, just missing the menu.
As far as no cost barred blu ray authoring, you’re probably looking at something like Scenarist BD, or Sony Blu Print 6. DoStudio Indie edition is another professional authoring program. All of these are very expensive. Sony Vegas Pro is probably a step down from them, but all of these are far beyond the needs of an amateur.