First, welcome to Islam.SE, and thank you for your contributions. We need more people to dive in, just like you.
Yes, having both halal-haram and haram-halal is just silly in my opinion. I think these arose because nobody noticed the distinction. And I think these can be diamond-hammer synonymized and very few people will notice. (It's proposed as a synonym here; if users would up-vote it, it can be done without a diamond moderator's intervention ["automatically approved when they reach a score of 4"].)
The remaining tags I discussed in How should we tidy up the halal/haram family of tags?. I've already manually edited out some of the mess. Now what?
My current opinion is that we should:
Use halal-haram for questions about determining whether or not something is halal or haram. It's a borderline meta tag, and shouldn't be used by itself.
This would eliminate the tags halal haram haram-halal halal-consumer sin sin-or-not, which are either synonyms or sufficiently close to synonyms to make their ability to index questions superfluous.
Use sharia for questions about sharia, e.g., how sharia courts operate, who determines what is sharia, what is the punishment for [foo], etc. Not for any random question that wants an answer that involves sharia.
Use fiqh the same as sharia, but for fiqh.
(And sometimes quran and hadith have been used to for what I would tag halal-haram, since they seek answers to "Is XYZ halal?" involving the Qur'an and/or Hadith.)
These tags have been ambivalently used for years now, so this is a huge change with long-term consequences. It needs to be considered carefully: what if it turns out to be a bad idea for a non-obvious reason?
My thoughts:
We should take our time and get it right. In the meantime, people can still ask questions and get answers without too much difficulty caused by this tag issue. So this change is not urgent.
I'm slowly implementing the above question by question. I'm keeping my eyes open if someone reacts unfavourably to the change. Noone seems to have objected yet.
If we want people to use tags appropriately, we need to provide guidance in the form of a tag wiki excerpt.
Usage guidance, also known as a tag wiki excerpt, is a short blurb that describes when and why a tag should be used on this site specifically.
I intend to systematically go through the tag wiki excerpts one by one (inshallah), but after I've removed unnecessary tags: Some micro-steps to improve tags (early 2017). Some of these will require individual meta posts to gauge the community's opinion.
However, my impression is that the highest priority of this site is getting people to upvote good-quality content. See: Some obstacles to graduation: self-moderation, question inflow, upvotes, and experts This will encourage people to use the site, and it will give people the reputation to be able to self-moderate the site and hopefully they will take up this role. (I recently made a list of questions here List of undervalued questions since 2016 which I think are worthy of upvoting.)
Finally, I wouldn't be too keen on talking about "irresponsibility"---it's not going to get anyone on board the "let's improve this site" train. And not everyone comes here to manage the site. And not everyone here has the expertise and familiarity with StackExchange to fix things without causing more problems than they fix. And not everyone agrees on the best way to improve things.