Man, I think the mere presence of looters in a kingdom will make Golem and HP worthless. Just a couple of ruins in your deck basically causes these cards to completely dud quite often. Once it happens a few times, there will be a snowball effect as the looting player keeps adding ruins to the Golem (or HP) deck. I guess with 200 different types of cards, it's inevitable that the presence of a few cards could render a few other cards obsolete. (Can anybody think of an example where that happens already? Lighthouse vs Sea Hag maybe?)
On the other hand, maybe I'm wrong, and the effect of ruins won't be as significant as it seems. Or maybe there are other DA cards that help the situation, if they're available, such as ones that specialize in hunting for and trashing ruins. Or maybe there's a +actions card which trashes ruins.
You're overreacting, I think. First, at WORST, Hunting Party will be a $5 Lab. Lab is already a $5 card. It'll ruin the traditional Hunting Party DECK (1 silver, 1 gold, 1 terminal silver, lots of HPs) but HP as a card will still be fine even in the presence of ruins. Whenever you get a Laboratory in a ruins-infested deck, HP would probably work no worse. It'll still skip over coppers and estates pretty well.
Likewise, you won't be able to make a "Golem Deck" where you get one or two actions and lots of golems. But there's nothing wrong with using Golem in a more standard way, as an engine component - it's still basically equivalent to Village+Lab (Draw 2 cards which are guaranteed to be actions and play them immediately) with, admittedly, a little less control. You'll want to play a Village before the golem because you won't have as much control over the outcome. But it'll still be playable. Perhaps a little too expensive, but still reasonable.
They won't be worthless. They'll be weaker, but by no means worthless.
(And, BTW, Masquerade does shut down, like, Sea Hag or something. It's not unprecedented.)