www.makemkv.com

What is the best way to go about doing this,

I want to rip with MakeMKV about 50 movies and create memorable short clips of each of these movies and compile them into one long video.

Other than using MakeMKV for ripping the source blu-ray, what editor is best to use for something like this? Adobe Premiere?

I also want it to be readable and playable on BOTH the PC (without DRM 'protection') and on TV (via bluray player with any other changes), so is this possible?

Yes, it possible, but you do need the technical expertise to do this, I have no need to edit videos, I only watch movies and TV programmes, so I cannot help, hopefully someone else will come along in this thread with a few suggestions!

You need a video editor that is compatible with the CODECs used in each of the source disks. Because several different ones may be used, you cannot assume a given editor is compatible unless you check.

While you could use a tool like handbrake to convert all of them to h.264 video, you lose some of the video quality for each conversion done.