I've got different criteria than you as I've stated before, but out of that group:
Haley - she has shown in her actions in SC and in her speeches that she both has a strong support for religious freedom and that she has a focus on policy rather than culture wars. She is the one I would choose, and it isn't even close. She also is former Sikh who converted to Christianity, now Methodist.
Biden - policy is not what I like, but Catholic faith does appear to be important to him. Policies put him far below Haley.
Trump - not only shows minimal if any fruits of the spirit, I have seen more than enough to believe he views support for religion when it is convenient for him. I don't trust him, period.
Kennedy - in fairness, he is here because I know little about him other than his repeated vaccines are bad claims. I haven't taken him seriously, so if it were Kennedy against Trump or Biden only, then I would have to look more closely.
Wolfgate, thanks much for your feedback!
Trump - Much agree with you his current state now. His support came from actions when he was President, revising tax code with Congress to increase standard deduction, kept inflation under control, building the border wall maybe a part of immigration issue currently discussed in Congress, and appointing Supreme Court justices with a Moral Compass, NOT since he was no longer President. Trump has had personality issues all his life, military school as a young teen, his lack of patience on the Apprentice TV show, etc. Lost my support as a future candidate.
Biden - Though he goes to worship regularly, and talks the talk, his walks the walk is questionable, his promotion of other than traditional marriage including his political appointees with some power doing some damage in this country not in line with God's thinking 1 Corinthians 6:9-10. It's not in line with traditional Catholic thinking either. Lost my support as a future candidate.
Haley - I follow your thinking. Though she crossed the aisle with Cathryn Jenner, hopefully not much more than an acquaintance. Unsure how much action she will take with immigration, though some work with e-verify she done in SC, unsure what other solutions she will offer. She has fewer issues than and not the investigations like on Biden and Trump. Other question have not yet found answer online about her is whether she goes to a conservative or liberal Methodist church, should make a difference to some. March 5 will tell what support she has and whether she is leading, 14 state primaries that day, in addition to IA(Iowa), NH, NV, VI(Virgin Islands), SC, and MI(chigan) before.
Kennedy - like you, have not researched him enough. In one poll without Trump running, he had 18% voting for him. Many others like us have yet not researched him enough either, and more could vote for him depending on their research, besides who is left after the Republican convention July 15-18. He has name recognition, similar to the two Bushes.
Some of my research came from Wikipedia, candidate websites, and other scattered articles.