I'd cost this at 4. I think it just seems elegant as a 4 mana 4/4, and it can't attack anyway. Cool card then!

Reasonable design; somewhere between Thrun, the Last Troll, Gorilla Chieftain, and Wall of Pine Needles. Slightly worse than all of them, but that's correct because this is artifact not green. A lot better than Clay Statue, but that ain't hard ;)

Only thing is, this isn't very much like a rare these days. In 6th Edition this would have been a rare, but these days it's somewhat disappointing as a rare.

Toyed with making it Indestructible but that would make it too good. Gave it first strike and its variable power instead.

Why not just say 1/4 deathtouch instead of that last ability?

Because its power is set when it is declared as a blocker, anything that later boosts the other creature's toughness doesn't boost the golem's power.

Well, sure, and it also behaves differently with Soul's Fire and other things. But in most cases, it just works like a 1/4 first strike deathtouch regenerator. (Which is a really irritating combination of abilities. Have you played against Voracious Cobra or Glissa the Traitor? Usually your only hope is to kill them out of combat... giving it regenerate as well will put lots of frowns on opponents' faces, which is probably bad when this card doesn't itself provide any way to win the game.)

reset to a 4/4 with the new text

To make this card playable i really think you should give it Vigilance, that would make the second effect more intresting.

As it is, its a 4/4 First Striking regenerator that can attack every second turn for 4 mana. I think that's pretty fair. Giving it vigilance as well would require upping the cost as a 4/4 First Strike Regenerator that can attack AND block every turn for 4 mana is kinda strong.

Plus, run it with Voltaic Key et al and its fine.