Your concerns would require a much more in depth response, but here are some highlights.

1. To millions (if not billions) of people throughout history the existence of God is unambiguous. God has revealed himself repeatedly. He rose his son from the dead. He parted the Red Sea. He picked out a devout people to hold onto his statutes through history. Doesn't it sound a bit petulant to demand that God personally reveal himself to every single person over and over again just because they have doubts?

2. Believing without evidence is not a prerequisite for salvation. God says those who have personal evidence are blessed and have been chosen, but that people who believe without seeing are just as blessed, if not more so. But not having a personal revelation from God is not a lynchpin for salvation.

3. Treating your fellow man properly does take precedence over faith. True Christianity is about following Jesus and learning to see humans the way God sees them. Now, modern Christianity and large swaths of Medieval Catholicism have major issues with this, but I would argue that they are not practicing true Christianity. I tell the people that I teach and mentor that understanding who God is, following the actual teachings of Jesus, and putting yourself in a mindset where you see people as inherently valuable are the most important tenets of our religion. Not faith or heaven or avoiding hell. Those things are overblown, and demanding a "sinner's prayer" is bad doctrine and has nothing to do with getting to heaven. In fact, the Bible (and indeed God) says very little about heaven. Jesus said that the Kingdom of God is here at hand and that eternal life is knowing the Father as he knew the Father.

I hope that helps.