In The Day of the Doctor Gallifrey was frozen in a single moment, practically disappearing from its place for the rest of time. Were the other planets in Kasterborous realigned / rearranged due to the disappearance of Gallifrey's mass and gravitational pull?
Although it's not specifically focused on Gallifrey, this quote from NASA Engineer Robert Frost gives a pretty good indication of how little even the largest planets actually perturb each other:
For example, take Jupiter. It is 1/1000th the mass of the Sun and 5 times farther away. So Newton's F=GMm/(R^2) indicates the effect of Jupiter on the Earth is 1/25000 that of the effect of the Sun on Earth. That is pretty negligible. It's possible Jupiter's contribution has resulted in a slight increase in the Earth's orbital eccentricity - but not enough that our lives would be different if Jupiter had never existed.
I think it's fair to say that if Gallifrey disappeared overnight, the actual impact on its solar system would somewhere between almost none and actually none.
I suppose it would but it wouldn't be signifficant. The Time War take Gallifrey from every Time Zone. It was never there, thats why the TimeLords will be kept as a legend that never existed, only as a story. Like when the Eleventh Doctor where erased from the Space-Time continium as a thing that never happened but it stay as a story. Well, the point is that there wouldn't be any distorsion in the constelation because there never where a Gallifrey.
From The Day of The Doctor transcript:
WAR DOCTOR: We're just about ready to do it.
GENERAL [OC]: Ready to do what?
DOCTOR: We're going to freeze Gallifrey.
GENERAL: I'm sorry, what?
DOCTOR 10: Using our Tardises, we're going to freeze Gallifrey in a single moment in time.
WAR DOCTOR [on monitor]: You know, like those stasis cubes? A single moment in time, held in a parallel pocket universe.
DOCTOR: Except we're going to do it to a whole planet.
DOCTOR 10: And all the people on it.
GENERAL: What? Even if that were possible
GENERAL [OC]: Which it isn't, why would you do such a thing?
DOCTOR: Because the alternative is burning.
DOCTOR 10: And I've seen that.
DOCTOR: And I never want to see it again.
GENERAL: We'd be lost in another universe, frozen in a single moment. We'd have nothing.
Freezing in single moment from the perspective of our universe meant surviving in another pocket universe. There's no reason to believe that Spacetime curvature (gravity) associated with Gallifrey mass would not go with it. So yes, it'd have disturbed the star system of Gallifrey (as for Kasterborous, it's the name of constellation. From that scale, there'd be no visible effect).
To prove that Gallifrey wasn't with zero Gravity (Time Lord tech), here's transcript from The End of Time (2):
(A big burning planet appears close to the Earth.)
SHAUN: Donna. Where's Donna?
(The tidal forces of the new planet make the Earth shake. Thinks fall off shelves.)
[Outside the Nobles' home]
(People are panicking as Gallifrey fills the sky.)
SHAUN: Donna? Donna! Donna!
SYLVIA: Oh, Doctor. Please!
ADDAMS: We're getting out of here. This whole planet's going to be knocked out of orbit.