I agree with you on the fact that the ontological argument has many flaws. As many of its arguments are based on the logic whereas humans prefer some observation to strengthen the outcome of deduction. Thus, I believe Stenger's objection to the ontological argument works as well because empiricism plays a big role in our daily lives and explore new knowledge and inventions.

He provides his objection in this form:
(1) If the ontological argument is sound, then you could know that it's sound without making any observations
(2) you would never know that any argument is sound without making any observations
(3) thus, the ontological argument cannot be sound

The Greatest Conceivable Being cannot just exist in our minds only but in reality as well. However, we cannot double this statement as there is no empiricism for the Greatest Conceivable Being other than the accounts of "miracle witnesses", especially when we observe the big problem of evil.

Could you provide examples of "depictions"?

I believe the topic opener just falsely abused the argument propositional form as any argument could seem to be valid according to the form but illogical.

I'll try to provide the alternative argument for this based on the instances of religions in particular Judaism and Christianity.

(1) If God exists, God provided moral values and duties to humans
(2) Humans wrote canonical texts based on God's instructions
(3) Canonical texts demonstrate the moral values and duties provided by God (1,2 HS)
(4) People shared the canonical texts to spread the moral values and duties provided by God
(5) These canonical texts, moral values, and duties exist now (3,4 HS)
(6) God exists now (1,5 HS)

This argument can work for God's existence as well as the problem of evil goes against the existence of God. Moreover, the argument is extremely vulnerable to religious pluralism as it uses religions as the foundation and many religions and their denomination have emerged in different time periods. Hence, I hope the arguments is just one of the arguments for God's existence.

The Fine-Tuning arguments are based on the prime principle of confirmation which favours the hypothesis under which the observation has the highest probability. However, Michael Huemer provides "the doomsday argument" where he provides two alternative hypothesis

(1) hypothesis 1: the human species will not last long into the future
(2) hypothesis 2: the human species will last long into the future
(3) evidence: you find yourself living in this primitive time with a relatively small population
(4)prime principle states: if some evidence is not improbable on hypothesis 1 but very improbable onhypothesis 2, then the evidence provides strong proof for hypothesis 1
(5) we observe strong evidence that the human species will not last long into the future. (1,2,3,4, HS)

Because Michael Huemer believes that we should view our existence surprisingly in the current time as a primitive time because humans will evolve into a more advanced future with the high population. But we believe that we live in advanced time with a high population compared to what was before, so according to Huemer the human species will not last long into the future.

Thus, Huemer provides the argument against the prime principle of confirmation, so this is the argument against that we should consider that someone aimed the dart because it seems to the most probable outcome.

I think the conclusion should include "morally permissible" as suicide is not socially approved across the world. The image of euthanasia differs from a person to person as some people do not relate it to suicide whereas others do vice versa. However, people are pro-euthanasia consider the various circumstances that qualify a person for mercy killing. Same goes for animals as humans practice it with animals who are terminally ill and suffer from pain.
Moreover, parents are always offered an opportunity to abort the pregnancy if a fetus is diagnosed with a genetic disorder, which may result in a shortened life of a child.

In Islam visual depiction of Mohammad and many other prophets are not encouraged by hadiths as well as not welcomed by Islamic scholars. Even if there was a depiction of such, Artists tried to express it spiritually rather than visually. Moreover, scholars throughout history did not promote it as they believed it would to idolatry. As a result, Islamic art is mostly geometrical and calligraphical.
Thus, they wanted to protect uniqueness and indivisibility of God.

I believe the boulder case does not depend on whether God can or cannot create the heavy stone but the argument merely focuses on a dilemma where either choice tries to convince you that God is not omnipotent. Probably, the flaw is in the premise itself, which defines God as not omnipotent if God cannot create such a stone.
Moreover, the definition of omnipotence plays a big role in each's perspective. As God who has infinite power can create infinitely heavy stone and has infinite strength to lift the stone.
I think, our definition of omnipotence in terms of a deity goes beyond logical and illogical possibilities as God is not bounded by these limits.

1. Either god can create a stone so heavy that God cannot lift, or God cannot create such a stone
2. If God can create such a stone, then God is not omnipotent
3. If God cannot create such a stone, then God is not omnipotent
4.Omnipotence is not bounded by human's logic
5. We cannot know whether God is omnipotent or not