Multiple answers is fine. I think it is fine to post multiple answers. If someone has multiple different approaches to the problem to suggest for consideration, I would prefer that they post multiple answers, rather than merging different approaches to the problem into a single answer. That way we can vote separately on each proposed approach.
The question is fine. I think the question is valid. It is a real problem, with broad relevance to web security, one whose solutions are not well-documented, and one that admits constructive and useful answers. If we look at secondary measures: it has received a bunch of upvotes from the community, and it has received a bunch of useful answers. I consider myself an expert on this topic, but I learned some useful new information from the answers here (especially one or two of @makerofthings7's answers).
As far as what it says that a question admits multiple answers, well, sometimes there is more than one way to skin a cat. Sometimes there are multiple approaches that can be taken to a problem, with none of them superior in all situations. At its core, engineering is about tradeoffs, particularly understanding the space of solutions and their tradeoffs. Often, there's not just One Right Way to do it, but multiple plausible approaches. So I don't think this is a shortcoming of the question at all.
I think the burden of proof is on detractors of the question to explain why they think the question is unsuitable. I've explained why I think it's a good question; I think the detractors need to explain in detail why the question is inappropriate.
Bottom line. I don't think @makerofthings7 has done anything wrong here. I think this is a great, relevant question that spurred some informative responses! We should encourage more like it.