I'm not sure if you can directly rip just the subtitle track from a DVD, but after ripping the video file, one way is to then open the video file with StaxRip, which will extract all tracks (video, audio, subtitles, etc.) into separate files.
I've tried handbrake but hated it, even just for simple things like re-encoding videos to a different resolution or codec it's just never doing what I want. I've switched to using Staxrip which was more clear in only changing the things I want changed and do H265 hardware encoding using NVEnc.
There are some pre-made encoding profiles but you can make your own including desired resolution and just always use that or even batch queue multiple videos. Like Handbrake it's also open source and actively developed.
Second the suggestion.
Also, you can try https://github.com/staxrip/staxrip, a video encoding GUI for Windows, it executes and controls console apps like x265, mkvmerge and ffmpeg and uses the scripting based frame servers AviSynth and VapourSynth for video processing.
I did something similar, but VHS to MKV. I used staxrip, as it's easy to use and comes with the best deinterlacer available, QTGMC...
You can give it a try: https://github.com/staxrip/staxrip/releases
> Staxrip is targeted towards automation
It says it's a GUI for Windows, and that doesn't sound to me like it's targeted at automation. Batch processing, perhaps, but to me automation means scripting or API, not GUI.
Bit of a late reply but was surprised this wasn't mentioned here at all; You could look into using StaxRip which is pretty much a GUI for tools like ffmpeg and NVenc etc. It's just easier to do things with, you can set up basically the same settings up in a profile and quickly queue up multiple files as a job before "batch running" all jobs. It also does hardware encoding with Nvidia, AMD and Intel.
It includes all required tools like ffmpeg and NVenc and those are regularly improved and updated, so you keep those tools up to date as StaxRip updates.
Handbrake is pretty good, but I prefer StaxRip for any (re-)encoding (I use it to downsize H264 scenes to H265). It's more straight forward with the settings, simply set input file, codec, container, quality settings, etc and go. It can also make full usage of hardware encoding (see the Nvidia/AMD/Intel profiles) so with a good CPU/GPU it'll take minutes not hours.
Best resolutions for devices is hard to say because there's so many different ones, here is a good article that lists a bunch of devices and their max resolutions.
If you want to do 5K or higher though, definitely look into using H265/x265 which makes smaller files of the same quality as H264/x264 (or higher quality at same file sizes). The main advantage for saving space is that you can lower the bitrate without losing much in quality, or perhaps even better to have a variable bitrate (VBR) while setting a maximum bitrate so there's a higher bitrate when quality is needed.
Still I suggest doing lots of testing, video encoding is a bit of an art in itself. I've searched everywhere for recommended VR H265 encoding settings and there's just no simple answer, it's very dependent on the video; resolution, fps, movement, colors, brightness... A default preset might work good for one video but terrible for another.