Hey good question,
If you are willing to learn vim, this is the absolute best way to do it. I’m a writer as well and vim makes my writing experience so much better.
Obsidian has vim keybindings built in, so if you are willing to learn you can just use vim for this kind of stuff.
However I recommend learning how vim works before you activate it, since otherwise you’ll just get frustrated.
I have a quick overview video about vim in Obsidian and I plan to make learning resources soon
Highlighting a sentence in Vim is as easy as shift + v but again in order to use this you need to first learn the basis of vim.
Solution without Vim
This wont work as well as vim, but it’s a lot easier.
You can use the arrow keys plus a combination of shift, control or alt if you are in windows or command , option if you are in mac.
It’s gonna depend on your computer, but as an example if you are at the start of a sentence, you can do ctr+shift + ↓ and that selects the whole link
Again this will change if you use mac, so experiment a bit with the combination of arrow keys (plus a combination of shift, control or alt if you are in windows or command , option if you are in mac) for different results.