I brought up the site in incognito and tons of shitty adds popped up about my IP being tracked or some stupid bullshit. I'm just curious if I'll get a letter in the mail about illegally downloading shit if I start to pirate software again.

piratebay was always safe
it was raided in 2014
nothing happened since then

Yes as long as you're reasonably intelligent. I don't even use a VPN, I'm just careful which torrents I choose. Recently pirated Infinite Warfare because it actually looked appealing to me. Sad the MP died already and everyone hates it. Seems cool to me so far.

Ublock origin + https everywhere + noscript + vpn + common sense 2017 edition will be safest at its best

Yes. I recommend you use a VPN though.