Is there any alternatives to Karabiner in Sierra, which lets you use whatever keybindings you like to open an application?

Solution 1:

You should try 'Keyboard Maestro' as an Alternative. You can bind actions to different Application-States as Macros, f.e. when Application X is open, do Y etc.

They offer a Testperiod, so you can try before you buy and test if it is meeting your requirements.

Solution 2:

I found that Hammerspoon is suitable for these sets of tasks. You write your own keyboard remapping, application shortcut, etc... on init.lua script. Some Lua knowledge might be required but if you have any programming experience in other languages, it is not that difficult.

I have implemented all of the tasks on the question except Move to the first or last part of the sentence, and it sounds working well so far. It took me some time (around 20 hours) to fight with the script, though.