Yes, the Shadow Lab works with just a Siver account.
I would suggest playing with Shadows instead of the AI. I think the AI can be fun a times, but playing Survival against Shadows in WAY better IMO, so I’d suggest doing that.
On topic though, yeah, the AI probably should get touched, that being said, the AI was pretty heavily touched already in Shadow Lords, so I wonder if the changes there actually had an effect in other modes too. All in all though, the AI isn’t the most…uh…consistent way to level up in any FG. At every level the AI is going to be exploitable to a degree, hell, this goes for static Shadows as well, so if you are looking for a real challenge, and you don’t have Gold at the moment, play in Shadows…with friends. 
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