Have you seen the roadmap? Many of those things are on the list already.
- Batch Transcode
You can already do that more-or-less. First, you can queue things up one-by-one. Secondly, you can drag-n-drop multiple files to the playlist and then Export > From > Each Playlist Item which will queue up every item in the playlist.
- Subclip Creator
This already exists more-or-less. Each playlist or timeline item is essentially a sub-clip. Except you can’t rename them. Also, there is nothing in the playlist to visually group all sub-clips of a clip. You can also save just a trimmed clip as MLT XML and then use the MLT XML as a virtual clip.
Sure, these can be expanded and improved upon - just like everything else given time and motivation.
P.S. Not only to you, but for all readers, it is better to make separate topics for each suggestion. That way as people “like” them, it can properly tally. If this topic gets liked, it is basically meaningless. Or if a bunch of replies accumulate - each with there own “I agree with point X” - it is harder to track and things get lost in noise.