Don't you think they should have been a little more sad about Tara Dying

I think they probably were. We just didn't get to see those times.

First they didn't really have much time to grief, because Will went insane with grief immediately at Tara's death scene and thus the others' minds and emootions were well occupied with keeping Will from destroying her life completely. Actually, I think that's a reason for why Tara's death may not have even sunk in for the others until Willow was brought back from the darkness.

And, at the beginning of the next season, they'd skipped at least some months ahead, I think the grieving happened during the time we didn't get to see. Of course it would've been nice if they'd had the others sometimes talk about Tara too, instead of just Will. But I guess there wasn't good enough spots for it in the scenarios, after all there was a lot going on with the First Evil at their doorstep and Tara had very little to do with its ways of showing up.

It kinda felt like they skipped over the whole loss of Tara thing, even after Willow came back from the dark. They all should have grieved her more in my opinion, and I think she made a great Scooby!

Yes, I think they should like have a funeral like Joyce had and should talk about her more often (especially Dawn, because she was very close to her).