What I want is the following:
Pressing TAB completes the current word I'm writing with the longest common prefix, and nothing more. I don't want to cycle through any options either, pressing TAB again should return me to the original string preferably, or do nothing if that's not possible.
Pressing CTRL + SPACE should pop up a menu showing all possible completions like the default vim.
Is this possible? I've found cycling through options / opening menus is extremely distracting for me while programming, and encourages the behaviour to keep cycling and hope that the completion I'm looking for is there.