Is Hamlet more disturbed by his father's murder or his mother's remarriage?
I think the two are inseparable. Of course, without the murder the marriage would never have happened, but I don't think that has any relationship to Hamlet's being "disturbed." It is very clear that he held his father in the highest regard. He presents the comparison in Act 3, Scene iv:
Look here, upon this picture, and on this,
The counterfeit presentment of two brothers.
See, what a grace was seated on this brow;
Hyperion's curls; the front of Jove himself;
An eye like Mars, to threaten and command;
A station like the herald Mercury
New-lighted on a heaven-kissing hill;
A combination and a form indeed,
Where every god did seem to set his seal,
To give the world assurance of a man:
This was your husband. Look you now, what follows:
Here is your husband; like a mildew'd ear,
Blasting his wholesome brother. Have you eyes?
Could you on this fair mountain leave to feed,
And batten on this moor?
The murder of his father might have been something Hamlet could have born with his mother's help; the fact that she was now married to his father's murderer made that impossible for him.