I'm usually friendly to strangers but I'd be immediately suspicious of someone asking me either of these questions out of the blue - and I'm a middle class, middle aged male.

It might be a cultural thing but yes, here in Europe I would be pretty suspicious of someone approaching me like that out of the blue. I mean, heck, that's none of your business!?

Smokers always have a reason to start talking to random people.

That's fine. Not every conversation turns into friendship.

Most of mine I am trying to find similarities or learn new things.

After the conversation is over, it won't matter how you opened, it won't matter if the person felt suspicious. I can't control your upbringing or your day.

You either are friends, or you likely won't see them again.

No one died.

A compliment or a question is usually a good way to start. "Oh hey, nice shirt, have you seen that band in person?"

lol I went to a local music venue a few weeks back and tried this. After inquiring about one guys shirt, he started at me for a few seconds like I was insane and turned around

If someone at a concert acts like you've insulted them by asking about their music related shirt, then the problem is with them, not you.

This is precisely why I don't feel bad about asking innocent questions.

If they can't handle basic conversation, it's them.

Then you have the perfect opener for anyone overhearing by cracking a joke about it.