1) Elizabeth should win here if we are discounting the blessings, since her ark is much stronger than the angels listed here. The only advantage the angels have over Elizabeth is better physical power and stats, but given that only Ludoshel has shown feats in this area, my answer is still Elizabeth.
2) If Zeldris has the Demon King's magic to use then he wins, otherwise the battle could go either way given they should be extremely equal combatants.
3) Elizabeth hands down. Her memory-less ark in a human form was enough to completely roast Derriere's hand. A full intentional ark from a Goddess Elizabeth would do exceedingly more damage. The difficulty here might be the 1v2 situation and trickstar, but besides that Elizabeth should win.
4) Elizabeth? I have no idea what Merlin has in order to effectively defeat Elizabeth in combat..
@Aldan could probably prove me wrong here though!
5) Elizabeth has superior magical strength and sustain in comparison to Escanor, but the prideful sin has better physical strength and feats in comparison to the Goddess Princess. But given Elizabeth should be informative of sunshine's power and abilities, potentially this knowledge could turn the fight around? I'd give it to Escanor for now, but at a medium-high difficulty given Elizabeth's strengths.
Here's one:
Goddess Elizabeth vs Meliodas with second demon mark.
Don't just say one or the other, give a reason. I think it could go either way considering Elizabeth has the elemental advantage, superior magical power, sustain and counter(?) to full counter. Meliodas has better battle experience, physical strength (etc) and the perfect defence against magic.
I'd give it to Meliodas ultimately, full counter is a big bonus for him and he has more experience in battle. But it would be medium to high difficulty for him, not an essay fight as one would expect.