Undersnatch
I agree with your first paragraph completely.
"I joined the app because I want to have a closer community. I want to get to know local people, help them out, be neighbourly. What you have written implies there is something wrong about that (there is, because male behaviour puts me at risk)."
It seems like you are wishing to be neighbourly, and that needs personal interaction with people physically close to you, and that you know that in the real world and online that involves added risk to you. We need a better society. And the app needs to discourage real photos and not publish precise street names.
"So I need to avoid public spaces if I don’t want random men I don’t know speaking to me? Is this what you are suggesting? Why did he PM me and not ask on the open forum if he was only interested in chat? I do think I need to leave the app, just like I need to avoid places where men like you think they are entitled to conversation with me."
Are you saying that men should never approach women unless given explicit consent first?
It wouldn't cross my mind in a million years to ask publicly first for permission to private message. I struggle to see the difference between public and private other than one is intended for a more limited audience.
I don't think I am entitled to a conversation - I think I am entitled to approach, just as you are entitled to make it clear that you wish me to back off.
"He was asking questions about a park I live close to. Seeing as the public forum is filled with people who live next to the park why would he select one woman to ask when he could canvass the opinions of many - if he really wanted to know. "
There was no need for that message to be private - unless he's looking for a friend or (more likely) partner. The problem here is not his approach, rather it is that you don't feel safe enough to tell him to get lost with no fear of repercussions. The latter won't change without society changing, which leaves the solution being society changing (equality) or men never approaching women... neither which seem that realistic.
"I cannot give you a definitive rule book, however put simply, many men present a risk to women. Many don’t and when you are not it may feel frustrating to be judged. But with respect, you are coming across as a man who thinks he has the right to mock/dismiss a woman’s boundaries and suggest that if she doesn’t want to be approached by unknown men then she should stay out of sight. This makes me uncomfortable and I think you should go and think deeply about what you have said here."
I don't think women are obliged to welcome unknown men approaching them, and I don't think women should stay out of sight. But neither do I think that women have a right to never be approached by strangers, nor men have no right to approach women, ever.
Meeting the public is an occupational hazard of being in public, receiving messages is an occupational hazard of being on apps that allow you to receive messages.
If I am right at the very least men need to learn to read the signs and back the fuck off politely and fast if requested or hinted.
I haven't got a point here really, I'm certainly not trying to win an argument or deny your experience... but I just cannot get my head around the idea that no men should ever approach a female stranger in public or by pm.