Ask first. Always. For everything. Really.

I'm going to disagree with this. Honestly, straight up asking can be even more creepy in a lot of situations. For example if you ask, "Can I give you a hug?", you've double creeped me out.

First, you violated my boundaries because we're not hugging friends yet if ever. Second, you violated my social norms by not reading our friendship hug level from the vibe of our conversation and my body language. You're right that I may not actually tell you "no" because it is more difficult to opt-out, but that doesn't make it less creepy.

There are some situations where asking is appropriate, but most of the time I would say if the social cues aren't clear err on the side of caution and later on ask a buddy who's good at that stuff what was going on in that situation and if you made the right call. Asking for stuff just tacks awkward onto creepy.