Someone who wants to do good for themselves and others, and doesn’t really care about following the rules in order to do so. But! also believes that most others are basically too dumb to be allowed to act similarly, and thinks they should follow the rules.
Neutral Good?
Sane? But, yeah based on the standard 3x3 grid, neutral good.
I thought part of being neutral was an indifference to the very existence of rules generally. The personality I’m thinking of thinks rules (the ones they agree with anyway) are a great idea, just not for them.
The neutral alignments can represent all sorts of middle grounds between the extremes. It can be apathy, or a little of one and a little of the other, or an active drive towards balance, or everything-in-moderation, or whatever.
That sounds like Chaotic Good to me. They do what they think is right with little regard for what others might think.
Yep, I concur. CG.
I’d go with Neutral Good.
The good part is easy. The Neutral part comes from a mindset of “Rules are fine and useful but shouldn’t be a barrier when they stand in my way for doing good”. Chaotic Good is more “Rules and restrictions are a barrier keeping us from really pursuing good”.
I haven’t played D&D for many years. And even when I did, it was a rather ad-hoc in-person group. So there were few if any set rules or templates?
But this sounds like “The Road to Hell is Paved with Good Intentions”. With a side order of Hubris?
Yeah. To me it sounds like a Lawful Neutral/Good character in the process of falling to Lawful Evil. “Laws for thee, but not for me”.
I’d call that “Calvinist” 
To me, they’re more Chaotic Neutral who thinks they’re Chaotic Good. Chaotic Asshole.
You can’t really be a good person if you think you’re better than everyone else.
Note to DMs- think carefully before you allow a CN character in your game. You will get some jerk moves, along with “but that’s what my character would do!” excuse.
What, exactly, are they defining as “good”, here? Because DnD Good is basically altruism, and binding others to rules you don’t personally follow is not that.
On the GvsE axis, it’s Neutral, and possibly Evil, depending on whether others’ adherence to the Law is merely advocated vs coerced by the person in question. The “doesn’t personally obey laws” part makes it not Lawful, regardless as to whether they think other dumbos should. So probably CN based on how it’s laid out in the OP is a good fit.
I, also, vote chaotic neutral. Or possibly true neutral. Despite what they think, i don’t classify them as good.
“Binding others to rules you don’t personally follow is not [altruism]”?
It’s a perfectly sensible idea. A parent may act such that they do as much good as possible to/for their child and they want the child to follow rules that they as a parent are not bound to. (I’d argue this is more or less the default position, if not the definition, of being a parent, but I digress.) The character I’m describing basically thinks of almost everyone else as permanent children, worthy of having good done to/for them, but not smart enough to understand the nuance of when rules need to be ignored or broken.
Alignment is pretty much dead in 5th edition. Gone are the days of spells like Protection from Good/Evil and there aren’t any magic items or traps that do damage to you based on your alignment.
Are they a god? Do they have godlike intelligence and wisdom? Because if not, they’re just an asshole.
It’s been replaced by Protection from Good and Evil, which provides general protection from undead, fey and extraplanar beings - meaning that it’ll protect you from angels and demons equally.
Sure, but the spell works by protecting you against certain creature types rather than alignments. Alignment no longer has any mechanical effect in D&D. At best alignment is a vestigal artifact of the past.