What are the two main reasons Macbeth gives in his soliloquy for not murdering Duncan?

In act 1, scene 7, Macbeth gives a soliloquy, where he outlines several reasons for not assassinating King Duncan. The first reason Macbeth gives for not murdering King Duncan is that the king's murder will only result in more bloodshed. Macbeth acknowledges that killing Duncan will not be the end of the affair and more bloodshed will follow. He fears that his bloody deed will come back to haunt him and motivate others to follow in his footsteps. Macbeth says,

"If the assassination Could trammel up the consequence, and catch With his surcease success; that but this blow Might be the be-all and the end-all here, But here, upon this bank and shoal of time, We’d jump the life to come. But in these cases We still have judgment here, that we but teach Bloody instructions, which, being taught, return To plague th' inventor: this even-handed justice Commends the ingredients of our poisoned chalice To our own lips" (Shakespeare, 1.7.2-11).

The second reason Macbeth gives for not killing King Duncan concerns the fact that he is the king's host and Duncan is his kinsman. Macbeth acknowledges that it is wrong to murder a relative and would be considered a great offense to harm one's guest. Macbeth mentions that a host should shut the door to prevent murderers instead of committing crimes against their guests. Despite Macbeth's reservations, his wife persuades him into assassinating King Duncan, which leads to more bloodshed and the corruption of Macbeth's soul.

Macbeth hesitates to go down the path of murder because, in general, violent deeds “return / To plague th’inventor.” In other words, in murdering any person, Macbeth will bring trouble to himself.
But more specifically, Macbeth offers two reasons for not killing Duncan. First, Duncan is staying under his roof, and under the rules of hospitality in that culture, Macbeth, as a host, is expected to protect his guests. Clearly, murdering one's guest is the opposite of protection. Further, as his subject, Macbeth owes a special allegiance to his king.
Second, Macbeth acknowledges that Duncan has been a good and "meek" king, by which he means Duncan has been a just ruler. In fact, Duncan has been just and good to Macbeth himself, making him Thane of Cawdor. How can Macbeth betray such a worthy ruler and kill him based on something as insubstantial as personal ambition?
It is likely that had Lady Macbeth not intervened, Macbeth might have dropped his murderous plan.