Would Christians still give to the poor/charity if they wern't Christians?

Sure why not? Lots of people who aren`t Christians or aren`t even religious give to charity, right? So having a little compassion for someone else is a good description of a Christian trait, but it`s not something exclussively Christian.

If you're asking if I would give to a non Christian, yes, I do it all of the time. If you're asking if I would have given to the poor before I became a Christian, then the answer is no, I would not and did not.

I think each person has to speak for themselves. If I was not a Christian I can see myself donating a little here and there, but nothing like I have been doing. When we our lives for ourselves, then we store for ourselves - however, when we are redirected into investing our time and money into people, then we do tend to be more charitable. The blessings we receive comes from God and the more we are blessed the more we are expected to be good stewards over what God has given us.

Yes, all are the children of God.