One flaw in all your reasoning. There’s no such thing, as “paying customer” in Free to Play/Free to Pay game. When you pay for an offer, it’s all you get from the offer. Nothing less and nothing more. Your opinion has same value as opinion of those who never spent a cent on game. Everyone is a potential customer that might pay in future, if they are offered something of value.
But, apart from that " I pay, I demand" attitude, I fully agree with you that kingdom helper offers should be adjusted to provide help with Power Levels 20+. With current design they aren’t helping at all, or even wore - they are “blocking” the slot, which could be used by other “more usefull” offer for other kingdom.