Still testing positive 7 days since my first positive. Can I go out now?

Yep, you're good but need to wear an FFP2 mask for the next 3 days. I was positive up to day 8 but only had a runny nose on the first 2 days.

It means that there's no way to know if you're infectious or not, so you should take reasonable precautions for another 3 days to avoid infecting other people, like avoiding or at least wearing a mask in crowded or badly ventilated spaces.

At 10 days almost nobody is still infectious.

Just get on with your life and stop thinking it's still a thing. It's not, nobody cares.

Yes, yes, yes.

As for nobody caring (not directed at you), well it might not be the massive public health crisis it was, but it's still a bad dose for a lot of people. My spouse was just wiped out for two weeks by it, now struggling to manage work in week 3, and she's healthy and not particularly old (under 50).

IMO it's just about being reasonably considerate for that extra 3 days.

How strict is the seven day isolation rule? I started to feel bad yesterday and tested positive. I have an event on next Thursday evening that I would like to be able to attend if possible. This would be towards the end of day seven.

If I did an antigen test that morning and it was negative, would it be OK for me to go out?

Thanks. I thought it was mandatory, not advisory. I guess it’s deliberately phrased that way, though I note they say “should” rather than “must”.

If you have symptoms, still testing positive, why don't you just isolate? Or is your need to be selfish more important?

You never said anything about a walk. You talked about an event next week in your post above. They only reduced isolation period so long as you wear a well fitting mask, this is something that never gets mentioned. So you're potentially putting others at risk even if you leave isolation after 7 days.