To save time, you only need to ask the others about the specific person you intend to frame. Ask the one you intend to frame about their relationship with the governor. As for dialogue choices, simply bring up your target's violent qualities or whatever makes them look abnormal.

Talking at the dinner table is unnecessary for the most part. Also, feel free to say no when asked about whether or not you spoke to the Governor beforehand, only the suicide ending needs this to be yes.

Alice the Servant Girl
Weapon: Dagger (guest room upstairs)
Evidence: Silver Chalice
Where to Plant: Her personal quarters in the basement (use pickpocket dialogue with Mother Bernes, also, listen in on the conversation between her and Nicholas in the beginning)

Brother Simon
Weapon: Mace (on the cart in the courtyard)
Evidence: Wycliffe's Bible
Where to Plant: In the courtyard

Mother Bernes
Weapon: Poison (plant growing near the wall in the courtyard, slip it into the wine in the chapel)
Evidence: Love letter found in Alice's room
Where to Plant: In the chapel room

Governor's Daughter
Weapon: Poison
Evidence: Bag of torture devices found in governor's room
Where to Plant: In the daughter's room

Sir John de Ashton
Weapon: Greatsword (in the hallway upstairs)
Evidence: Debt collection letter on cabinet table
Where to Plant: In the guest room where he is staying

Nicholas the Steward
Weapon: Hand Axe (on the tree stump in the courtyard)
Evidence: Hair lock found in the daughter's room
Where to Plant: His personal quarters in the basement (when talking to Sir John, be sure to bring up the question of why Nicholas is a bachelor)

Suicide
Weapon: Poison
Evidence: Hair lock found in the daughter's room
Where to Plant: His personal quarters upstairs (when asked, say you spoke to him and that he misses his wife dearly)

You Die
Weapon: Bare Hands
Evidence: Does not matter
Where to Plant: Does not matter (you will get into a struggle and be thrown off the top of the tower)

Confession
Weapon: Anything but poison or your bare hands
Evidence: Does not matter (just pick something to advance the game)
Where to Plant: Does not matter (you simply need to get it off your person)

This one plays out differently than the rest. I set the entire murder up as if it were done by Nicholas, although your target suspect should not matter. Upon killing the Governor, stay on the rooftop and wait for Brother Simon. He will ask what happened and then you will have the chance to admit to what you did. Once the sherrif arrives, he will only make you and Brother Simon suspects, so there will not be many chances to bring up someone else. All you have to do is play it off and redirect all suspicion. If your weapon of choice is not Brother Simon's mace, the murder will remain unsolved and no one will be arrested, thus ending semi-peacefully.

When talking to Sir John, do NOT bring up your family's heritage or legacy. This will make you look like a prime suspect later on. Instead, say that you are a commoner and that your father was a merchant (or similar profession).

When asked by Mother Bernes about Wycliffe, say that you do not get along with him. Otherwise, you will look like a supporter of the heretics and thus a viable suspect.