Answer: 

A.  What a great question!   This is an example of an "apparent" contradiction in the Bible.  This is what I have learned about such examples.  They are not in fact contradictions and when one understands how they are both true, one gains a new and deeper understanding of the Bible.  Of course, all the words of the Bible are true.   The fact is that all along salvation has been only by faith.  As the Hebrew writer says, "without faith it is impossible to please God." (Hebrews 11:6).  Yet, Jesus said "My yoke is easy and his burden is light" (Matt 11:29-30).  Without faith nothing is possible but with faith everything is possible.  Salvation by obeying the Law of Moses is unobtainable, but
He who by faith is righteous, shall live." (Romans 1:17, Habakkuk 2:4).  All the scriptures you quote above should be read in this light.  Deuteronomy 30:11-12 is calling the people to make a decision, by faith, to follow and serve God with all their hearts.  This is not impossible for them.  It is not "beyond the sea."  It was then and is now obtainable through faith in God (and through God’s grace of course).  The Turkish translation may not be the best.  My English version says "The command I am giving you tosay is certainly not too difficult."  What command was this?  The command is to "choose life, love the Lord your God, obey him and remain faithful to him." (Deuteronomy 30:19-20.  Now, if God had said to Moses.   "Keep every command in the Law I am giving you without ever breaking any of these commands and remain righteous before me by your own works.  This will not be difficult for you"  That would be untrue!!!   So, I agree with Exekiel 20:11, but I interpret it in the light of the entire Bible.  It is true that if we keep every one of the laws we will live by them.   The problem is that none of us can do that.  Like Paul said, there is a sense in which the Law became a curse, because we could not keep it perfectly.  It had the effect of teaching us that we are all law breakers in need of faith and the grace of God.  This fact does not upend Jesus’ statement that his yoke is easy or the statement in Deuteronomy that it is not too difficult for us, because both of these statements imply living by faith under the grace of God.  Is the Law doable?  Absolutely not!  That is the clear message of Romans 7 and the entire book of Galatians.

B. The person you are quoting from is obviously trying to get you to doubt the biblical teaching that Jesus is God.  Although I certainly will not agree with his conclusion, his point is at least partially valid here.  In other words, just because the apostles called Jesus Lord does not mean absolutely for sure that they were identifying him as God.  When the blind man said to Jesus "yes, Lord" in Matthew 9:28 I do not believe you can prove that he is assuming Jesus is God.  Lord is a title, not a name and it is a title of deep respect and submission.  We all know that kings were called Lord.  However, there are times when the word Lord was definitely and without doubt used to refer to the deity of Jesus.  For example in John 20:28 Thomas said to Jesus "My Lord and my God."   Only one with a very strong commitment to denying the obvious would try to make this a reference to two different people.  This is silly.  So, there are times when the title Lord was used for Jesus when the one using that title was very clearly using it as a title for one who was seen as God and there are times when it was not.  The one you quote is trying to twist this into an argument against the deity of Jesus.  The problem with this is the dozens of passages which very clearly point toward the deity of Jesus.  Here are a couple of examples:  Matthew 28:18 has baptism being in the name of the Father, Son and Holy Spirit.   Jesus is described as “our great God and savior” in Titus 2:13.  Yes I am aware of the textual gymnastics JWs do to get around this passage, but the fact is that no biblical scholar supports their bogus translation.  In John 8:58, Jesus says “before Abraham was born I AM”  Here Jesus takes for himself the Aramaic equivalent of YHWH as his name.  Naturally, at this point the Jews tried to stone him, because the implications are crystal clear.  In fact, he was accused of making himself out to be God in John 10:25-33 by claiming that he and the Father are One.  If they were incorrect in accusing him of claiming deity for himself—in other words if he were not in fact God—then surely he would have cleared up their misconception!  John 1:1-18, Coll 1:15f, Hebrews 1:1-4….  I could list a dozen more passages which show unambiguously that Jesus saw himself as deity and that the apostles after the resurrection saw him as deity as well.  Matthew 7:22 is another place where the title Lord is being used of Jesus in a way which clearly points toward his deity.  Here Jesus is the judge at Judgment Day.  Your author is again trying to confuse you by the way he uses Revelation 11:15.  Although "Lord" is very clearly used of Jesus as God in John 20:28, in the Revelation passage it is not immediately clear.  More likely, here Lord is a reference to the Father and Messiah is a reference to the Son of God–Jesus Christ.  Of course whether or not this shows Jesus is God or not is not proved either way in this passage, but there are plenty of places, including in Revelation, where Jesus is clearly presented as deity.

C.  Again, I can tell that the one you are reading is trying to create a deceptive argument against the divinity of Jesus.  You should be careful about such Satanic arguments.  Here, one must separate a name from a title.  YHWH is a name while Adonai is a title.  YHWH can, obviously only be used of God.  Of course, Jesus said "Before Abraham was born, YHWH (I AM).  Jesus called himself YHWH in John 8:58.  But never mind that for now.  This author is trying to confuse you by using a partial truth.  Yes, Abraham is called Lord.  Kings and earthly masters are occasionally called Adonai, which means Lord.   God is also called Adonai hundreds of times in the Old Testament.  The mere fact that Jesus is called Adonai in Psalms 110:1, by itself, does not establish whether Jesus is or is not deity.   Given that both Abraham and God are called adonai in the OT proves that this argument can go both ways.  Now, what your deceptive author is doing is trying to use this argument to prove that Jesus is not deity.  It does nothing of the sort.  The deity of Jesus is established in other passages.  By the way, I think the passage Psalms 110:1 very strongly implies deity of Jesus.  I would just say that his deity is not PROVED by this passage, but just supported. 

D.  I do not understand this question.  Can you clarify for me.  "Isaiah 53 is written in the past tense."  It is true that the verb tenses in Isaiah 53 are in the past.  The answer is that of course Hebrew has a future tense.   I think that your author is trying to produce some sort of argument that Isaiah 53 is not a prophecy.  This is a rather weak argument.  Even the Jews understood this to be a prophecy of the Messiah.

 John Oakes, PhD