What addon functionality ought to be in the vanilla game?

[betaking]

rather than mechjeb... which I know is controversial,

what about kOS?

particularly if said implimentation of kOS did not have access to globalvariables for a craft, but rather had to get its information through sensors or transmitters.

it would allow for automation, but at a noticeable difficulty.

I think remote-tech -like functions should be added, though for science-transmission only if there are no difficulty levels (meaning you'd still be able to control the craft, just not transmit science from it).

Aerodynamics, including far and deadly re-entry should be added as well, they offer challenge.

some more parts, preferbly ones that are fairly modular or proceedural (possibly like proceedural fairings, structural beams/panels/girders, or interstages/fairings (rather than the automatic fairings/interstages engines have now)

[Lheim]

Can you hide/minimize the UI for it?

When you don't have the dialogue open, there's just a little green icon situated by default at the bottom of your screen.

[Tank Buddy]

I would like to see craft mass in the VAB, but not the Delta V because that would be too easy. I'd also like to see a protractor for interplanetary launches. Maybe even an alarm that you could set so you could play worry free while you wait for your interplanetary missions to reach their destinations.