These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Harsher in Hindsight: Early in Shadow Kiss during the guardian practice exercise, Rose wants Dimitri to have the opportunity to show that he could be a badass Strigoi.
In Blood Promise, Rose notices that Sydney doesn't seem to eat much of her food, but doesn't think much of it, and actually steals some of her fries. It's later revealed that Sydney has fairly severe body issues.
Ho Yay: So so much Ho Yay between our main characters. Especially in the final chapter of Shadow Kissed and a lot of Blood Promise. The part where Rose leaves the academy and heads to Russia is pretty much like a break-up scene, you don't even need to change the dialogue.
Les Yay: Lissa and Rose's relationship can and sometimes is interpreted this way, to the point of being lampshaded.
For more, check out the trailer for the film adaptation.
Like You Would Really Do It: The scene where Christian turns Strigoi, invades St. Vladimir's, kills Dimitri and even goes as far as turning Lissa, before they all circle around Rose threateningly. Yeah, it was pretty obviously a Dream Sequence.
Special Effect Failure: The psi-hounds are laughably bad. Also, Christian setting them "on fire" wasn't very convincing either.