I think there's too much weight being placed on washing Buffy's bloody laundry. I highly doubt secret-Slayer girl would toss every bloody peice of clothing into the hamper; she probably took care of the heavy stuff herself and left the smaller spots on clothes her mom would do.
Also, to the comment about not knowing much about Buffy's life: She had to keep her Slayer identity a secret, which was pretty much her extra ciricular activity if not primary. When one has a secret that is a huge part of their lives, doesn't that (secrets) seep into every other aspect of your life? How could she explain Angel? That would lead to questions which might blow her cover. The only reason Buffy blew her cover was because there was no turning back from dusting a vamp to protect her mother right infront of her. I know that I'm like that, my parents get on me for not knowing much about my life even when I was living with them. I was too busy out and living it to come home and discuss it, discuss people they don't know, what's the point? Also, sometimes, I didn't want them to know. I was too independent at that age and I think Buffy was too.
As for the Ted thing, yeah that was lame. However, how lonely was Joyce? She found a man who was willing to take care of her, she was probably in a desperate place emotionally. And then her daughter, who's known for getting in trouble, starts to get moody over her new "dad." Typical, I'm sure Joyce figured; a single parent's kid is acting up over a new parental figure in their life. So, to say Joyce was selfish here ignores the fact that Joyce may have thought Buffy was selfish and as a parent who wants the best for her kid - stability and a family - she felt it out a bit longer (which challenges Joyce "being selfish."). Not saying it was right but I doubt if she thought it was any more than Buffy reacting to a potential new father she would've ended it.
Joyce didn't actually kick her out of the house. Really, does anyone think she meant that? She even says, "Mom's not perfect, ok, I handled it badly." In the morning, she went to check Buffy's room for her, probably to appologize! We love so many characters for their faults yet are coming down on Joyce for hers. She wasn't a single parents for very long - from how I understand it was right before Sunnydale. She was learning too. Anyway, telling Buffy that she couldn't come back if she left the house was her last ditch effort to get her daughter to stay after physically being stopped by Buffy. That scene was beautiful, as if balanced Joyce the mother with Joyce the person. If she wouldn't have tried to have given Buffy a bluff at the last moment in such an authoritive mother tone then I could see her being criticised for that, too.
I'm not necessarily a fan, I like her well enough, I just think she's being judged here rather harshly! I think she did pretty well for raising a daughter who burnt down a gymnasium, had to make her move, probably a factor in the divorce, who snuck out and was cutting classes, was witty beyond belief, who didn't listen to her (did Joyce ever get that dress she wanted from the mall in Bad Eggs, hmm?) and who didn't tell her a damn thing when she layed on her shoulder in "Innocence." She tried to understand in so many ways once she knew the truth and, in her own mother way, she did. As annoying as her questions and statements may have been, they were all outta understanding for a lifestyle she had just been introduced to.