I believe a close reading of the referenced verses will show that none of them contradict what Paul said in Ephesians.
Romans 2:6-7 talks about how God will repay each person according to what they have done on earth. Indeed, we are storing up for ourselves treasures in Heaven. Paul was not stating, much less suggesting in this verse, that one must work to get one to Heaven. Indeed, it is a free gift. See Romans 6:23.
Romans 2:13 needs context, which can be found in the preceding verses, in which Paul is telling talking about Jews at the law. He is responding to the belief of his Jewish brethren who believed being under the law and hearing it would save them. However, Paul is saying in these verses that in order to be declared righteous in God's eyes, one must obey the law. In fact, Paul will later point out that a person living under the law would have to obey the law perfectly, in every way, in order to be declared righteous by God. Nobody was able to do that until Jesus arrived, as Paul later says in Romans
Romans 6:20-23 talks about being a slave to sin rather than slaves to God. Indeed, "For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord." 6:23.
Ephesians 5:4-7, just like Romans 6:20-23, talks about the kind of person a Christian should be and aspire to after becoming a slave to God.
2 Cor. 5:10 is talking about the "Bema" seat of Christ the special judgment that God will hold for believers only (i.e. people already saved).
Philippians 2:12 is often misused to instill fear into people, warning them that it means that they can lose salvation. We can do an entire thread on this topic, but in short, the idea that Paul was saying we have to work toward salvation, which is how some people have interpreted this verse, is not supported by the verse itself, or Paul's other teachings in scripture. There are a number of good commentaries on this verse I would suggest looking at.
James 1:4 talks about persevering so that God can finish his work in you so that you may be mature and complete. This is the process of sanctification, not salvation, which is quite different.
Finally, Hebrews 10:26-27 is speaking to people who have heard the gospel, have come face-to-face with the claims of Christ, perhaps have been associated to some extent with His church, but strayed, which of course suggests they were not believers in the first place. Again, this is not a suggestion that salvation requires works.
Jesus said it best in John 3:16: For God so loved the world that He gave His one and only Son, that whoever believes in Him shall not perish but have eternal life." Notice there is no mention in there anywhere that Christ required some work on the part of the Christian in order to get to Heaven. If he did, as Paul said, then it wouldn't be by grace you are saved. And thank goodness for that.