Thanks for replying Appealing. I have given some thought to the questions asked to hopefully provide you with decent feedback.
A1) The infernal capes consist of 3 capes belonging to each combat style. Do remember that a cape isn't as worthy of a grind as compared to an obby set from its bosses. I understand that the cape is considered end game tier and thus has been factored into my thought process. I, a player who would slave any boss day and night for it's drops provided its worth it, would be happy to spend at least 15-20 hours per cape on average. It'd be more than acceptable if the capes aren't tradable provided that no dupes are obtained.
A2) Unfortunately not. Would rather not do the same content for over 100 hours.
A3) The RS3 armours are considered dps armours. Meaning they should have better attack stats but lower defensive stats. They would be placed above elite obby at the cost of much lower defensive stats for players to not be able to afk bosses which is the case almost everywhere now. However given that we have custom weaponary in game such as elites, it makes this difficult to decide for the RS3 weapons. This decision would be solely be for the admin team