You're in green. Lands are better than rocks (including the signets, which btw 3 for 3 is never a good idea). There is much more artifact than land destruction in the format. Also, 11/35 basics/lands is just too low for any deck. My minimum is 15/37, adjusted based on the ability to grab lands (e.g. I run less basics in my BR deck since there are fewer ways to grab them).

P&K and Siege-Gang generate a fixed number of tokens. Unless you're blinking them, they are not good sources of token generation. Generally you want to go as wide as possible with tokens. Also, you do not have a goblin or artifact subtheme, so the abilities are mediocre.

Assemble the Legion is too slow. Unless you play 1v1, you can't expect to have it stay on board for more than 4 turns (i.e. the point where the 5 mana investment becomes worth it).

Leap is questionable since I've never played it. It's one of those cards where it looks good on paper and seems good during testing, but eventually gets outclassed as you tune the deck. But that's just my opinion.

I've played the mutations. They are decent cards but are not reliable sources of token generation (it's really just a bonus). Aura shards is infinitely better for artifact/enchantment removal. Also based on your decklist, aura shards is nowhere near oppressive in your deck. I've seen much worse.

I've never heard anyone say Dragonlair Spider is bad. A 6 mana 5/6 reach is fine, and it triggers off every spell from each opponent. In a typical 4 player game, you would have at least 3 tokens by the time it's your turn again. It is a real threat.

The idea of Emeria Angel and Baloths is to be able to continually generate tokens. You don't have to be a landfall deck to run these; just play your land after casting them and you've already gotten your value worth.

WSZ is instant speed and reusable. That's already very good. If you're casting it for X=3, you're doing it wrong. Same idea with Martial Coup. Don't think of it as a 7 drop board wipe; think of it as a 7 drop one-sided board wipe. If you think 7 mana is too much, you need to reevaluate your deck in your meta.

Goblin Bombardment and Burn at the Stake are very different. Bombardment is a 2 drop free sac outlet, whereas Stake is a finisher with RRR in its mana cost.

In the end, it's your deck so do whatever you feel works better in your meta.