Steemit Tags,Importance of the 1st Tag and Need to Get it Right

I'm fairy new to steemit, and I'm still finding my way around the community. I just want to share my experience(with the hope that someone will learn from my mistake) with steemit tags and what it could potentially cost you if you get it wrong.

Sometime I ago I made a post that's suppose to b tagged NSFW but due to some error I mistakenly tagged it NFSW, it was not until the post got downvoted into oblivion that I saw the mistake I made and it also cause my reputation to drop from 25 to 15.

Discovering the mistake I open the post for editing, to correct the mistake I made with the tag, the I discovered that every other tags on the post could be edited except the first tag (I guess its used as the main tag of any post).

This implies that the post will forever live on with the mistake.Since then I've learnt to check my post over to avoid such mistake.