And I am a Willow/Oz shipper, and I know someone is going to say "she wasn't stringing him along, she was confused". However, if Willow had begun seeing a new GUY, we all would've been like "Oh, she totally lead him on"
I can't speak for the entire audience but if Willow, as the wronged and abandoned party for months, took a less than a day to tell Oz that she was just starting to date a new boyfriend because she felt torn between Oz and the new guy, I wouldn't have described it as "leading him on". Indecision with unfortunate grievous consequences but Willow never promised Oz a relationship or started physical affection or anything like that.
And I don't think that you can evaluate this without considering the position of gays in 2000 in the United States. When anti-sodomy criminal statutes were constitutional and gay marriage wasn't even a topic of discussion and where on this show, Joss Whedon had to threaten to resign for Willow and Tara to kiss in S5. There's a reason why coming out is treated so seriously among LBGT and their allies. Even beyond homophobia, I more than understand why Willow was afraid of hurting Oz by telling him that there was this whole big side to her sexuality and self that he wasn't and couldn't be a part of. It's never, especially back in 2000, as simple as saying, "Hey, I'm seeing someone new" particularly since I'm SURE Oz's next three questions would be, "Who is he? Do I know him? Can I meet him?"
For the record, I don't blame Oz for wolfing out either. That was a physiological change beyond his control and it's something that his human heart was enough to start overcoming the change to warn Tara and to leave Willow gracefully and respectfully.
Even if Oz hadn't wolfed out in the daylight before, do you think Oz would've been calm if he had discovered the Willow/Tara thing minus the transformation? I don't think so. Oz rarely loses his cool but if he felt Willow was open to them starting over enough to actually re-enroll into UC Sunnydale and then found out she'd been stringing him along, he'd still have been pissed.
Maybe I just have a higher opinion of Oz, but I'm sure that he wouldn't have been a danger to anyone if he didn't wolf out in the day. His feelings would have been hurt either way. They were probably marginally hurt more because Willow's reception and Xander's report of "no guy" really made him think that there was a big chance that he could be with Willow. However, he would never hurt Tara except for the completely unforeseen wolfing out in the day.
I also saw no indication that Willow knew that Oz was re-enrolling back at UC Sunnydale. I also saw Willow wavering in her feelings and feeling all kinds of affection and care for Oz come back and he probably sensed that and inferred that they had a future together. However, I never saw her give him promises that would lead her to believe that he was going to, shock of all shocks, finish his college education all for her and that means she's guilty.