Basically, I've been trying to rethink the current set of slivers as less aggro, and more control. Yes, you can use them for aggro, and they still technically function that way nicely, but the control aspect and the fact that just about everything in the deck is some sort of threat which attracts a lot of removal has led to my current mindset.
I can generally get a first game win from someone who hasn't seen the deck before, but that is usually due to the opponent not really understanding which of the slivers are the biggest threat. Once they figure that out, I have to rely on the control aspects I've added, as well as having multiples of each sliver to play, to mitigate the impending removal, at least long enough to drop some heavier bombs like Sliver Hivelord
Depending on how play goes, I think I might switch out a Blood Crypt for a second Breeding Pool, or Temple Garden. We'll see, but so far during testing it hasn't proven to be much of an issue, as long as I can get a manaweft and a green source on the board, though that can be compensated for with Mana Confluence and Sliver Hive rather nicely.
The Sideboard is more of where I'm kinda unsure with this deck. I could probably use another Thoughtseize in the deck, but I feel comfortable with 3. I was also thinking of maybe another Mizzium Mortars just to even up the odds of pulling it when I need it if I sideboard it in. The basic idea is to be able to tailor in a bit more removal specific to the threats of my opponent, or add some more aggro aspects through Striking Sliver. Additional removal for other things like enchantments and artifacts would most likely replace the Devouring Lights. I considered
Deicide
for the sideboard as well, but I'll add that depending on the local meta.
Overall I really just built the deck to be able to have fun playing one of my favorite tribes during that weird time with 2 core sets in play, while waiting on Khans to come out, and present new ideas and decks to play, because I don't think it'll be viable with the landbase available after rotation, or with the loss of key slivers like manaweft.