SuttaCentral
To the first point regarding arahants (and I must admit to my student-level understanding), if an arahant experiences an unpleasant feeling to have arisen in the mind, they know it for what it is according to their understanding of causal conditions. Importantly, they do not generate further kamma at any level of the cognitive process.
It’s a fascinating area of discussion.
Suppose a dog on a leash was tethered to a strong post or pillar. It would just keep running and circling around that post or pillar […like clowns who…] keep running and circling around form, feeling, perception, choices, and consciousness.
I enjoy how Ajahn Brahm talks about the development of jhana. Only by progressing into the next jhana can you see the previous one as suffering/not as good. Experiences of the mind that people call union with God, and from a higher perspective, it’s suffering.
Wowza!
Yup, thanks. I had read more suttas since posting the OP, arahants can experience unpleasant feelings too. It’s the first arrow of suffering, but arahants don’t experience the second arrow.
This primary (first arrow) and secondary suffering classification are better than physical/mental as unpleasant feelings are commonly regarded as mental suffering for most.
“they know it for what it is according to their understanding of causal conditions.”
If it refers to DO this would be incorrect. The discernment that cuts the fetters is of the impermanence of conditioned phenomena. The study of DO is dangerous in this way because it subverts what is the main and simple logic in the process of insight.
Ven. Nandaka the foremost advisor of nuns:
“So then, sisters, what do you think: Is the eye constant or inconstant?” “Inconstant, venerable sir.”
[…]
"This simile, sisters, I have given to convey a message. The message is this: The substance of the inner flesh stands for the six internal media; the substance of the outer hide, for the six external media. The skin muscles, connective tissues, & attachments in between stand for passion & delight. And the sharp knife stands for noble discernment — the noble discernment that cuts, severs, & detaches the defilements, fetters, & bonds in between.”—-MN 146
For beginners, this is one good way to explain 3 types of dukkha.
I think you explain it for beginners. 
Regards to arahants? does not seem to fit such a narrative. Also for sotapanna maybe such projections of the 3 types of dukkha will not fit.
So what’s the difference with respect to the ariyas? Can provide sutta support if possible?
“If clung to” is cause of dukkha (next rebirth, next existence, next experienve)
Nibbanadhatu is dukkhanirodha
Good point 
Impermanent/ change (viparinama) and conditionality (sankhara) is character of dukkha. Everything that has the character of change and is conditioned is dukkha.
Most people get caught up in “experience”. Thinking that dukkha is just a matter of experience. So the translator uses the word “sankhara produce dukkha”: in his assumption, because is one doesn’t like sankhara, his mind becomes dukkha. Here it is stuck. Whereas dukkha as an uncomfortable experience is the first type of dukkha: dukkha-dukkhata. Two others types of dukkha are reality in everything but nibbana.
I change my mind again, due to this:
Thg 248
Those who
for the sake of sacrifice
for the sake of wealth
we have killed in the past,
against their will
have trembled and babbled
from fear.
But you —
you show no fear;
your complexion brightens.
Why don’t you lament
in the face of what’s greatly to be feared
[Ven. Adhimutta:]
There are no painful mental states (domanassa), chieftain,
in one without longing.
In one whose fetters are ended,
all fears are overcome.
With the ending of [craving]
the guide to becoming,
when phenomena are seen
for what they are,
then just as in the laying down of a burden,
there’s no fear in death.
I’ve lived well the holy life,
well-developed the path.
Death holds no fear for me.
It’s like the end of a disease.
No , they may not commit suicide on hearing life is suffering , bhante . Never heard of , yet . 
It seems for beginners they like to hear something matching to their desire . As can be seen they like to give , make offering , in return , they gets more . Thats seems what the Buddha taught to lay people . Then the Buddha said , if you perform evil deeds , disaster would be following . Lay people do not want to end suffering , they wants to achieve a satisfying , pleasurable and extra enjoyment in their life . 
. Only failing that , they thinks of suiciding .
Please also read M.N.2