Some Christians believe that good works are "filthy rags"....
The bible says, faith without good works is dead.
I believe, (as the bible also states) that we are 'saved by faith not by works lest any man should boast.'
I get a good combination of Catholicism and Bible believer combined. The bible church or whatever you call it, Evangelical..teaches us to pay more attention to God's word, which I was never encouraged to read my own bible when going to the Catholic church.
At the same time though, many Catholic things that are very important are NOT found in the bible church.
You will not have the beautiful gregorian chant or hymns for example, and they don't have the beautiful portraits of Jesus which are SO inspiring. Looking at a crucifix also, is not a bad thing, Its VERY IMPORTANT in my opinion and my experience to --meditate on Jesus's passion and death-- in order to be closer to Him.
But to answer your questions specifically,
Humans have to participate in God's grace; it's unavoidable.
God provides grace- or situations or people in our lives that can and will lead us To Him. one of these is suffering.
We can get God's grace which He gives to all, offers to all, but yes, our will is necessary to choose to follow or not.
Yes, i believe since God wants us to pray, especially for others , for sinners to be converted as well as for ourselves, praying for others is a charity and an action put forth from "love one another as I have loved you" well then pray for one another as St. Paul did!!
yes God will reward works-- of course we can't earn our way to heaven. But he will give more grace to us if we pray more and all of these things will lead to a desire to do more good things and good will benefit ourselves and others....As for people being more saintly than others, I don't feel we should compare.
No, every human participation in God's grace is not completely a gift of God, because if it was, it would mean we had no freee will and would be as puppets with God doing everything.