Jewish neighbor

Hello cousins (Muslim here). I grew up in a diverse neighborhood with many Christian and Reform Jewish neighbors, but have a few questions.

So, I am aware that, as in Islam, there are different interpretations of Jewish law. I just want to mention that as it may save time in replies.

I have new neighbors who are Jewish, but I can’t really determine what denomination they are.

As far as I can tell, I do not think they are Orthodox as the husband does not regularly wear a Yarmulke, and I have never seen Tzitzit. Some days he has a Yarmulke, but most days he does not. The door does not have a Mezuza.

Here are my questions:

1. I was going to give them a bakery item as a gift (Kosher). Does it ever happen that a kosher item is not accepted from a non-Jew? I have read that historically, Jews did treat items received from Muslims different than items received from Christians (more accepting of items from Muslims).

2. It so happens that I have been a Shabbos Goy in the past. Is this something that should specifically not be mentioned in conversation?

3. While Muslims also view God as holy, Muslims do not have issues with mentioning God in conversation (we have phrases such as God-willing, etc). I don’t suspect this will come up, but is it offensive to mention “God”?

4. Muslims eat Kosher meat. I was going to ask if they knew if any Kosher butchers. I figured this is fine but also thought to check since I am already making this post.

Anyways, thanks in advance

Edit: From a brief conversation, the husband and wife both attended Jewish schools and Yeshiva University.