According to SDA can all pastors forgive sin, or just the original twelve apostles?

xybrek, I don't think this verse has anything to do with forgiveness of sins. The bible teaches that no one can forgive sins but God:

Mark 2

5 When Jesus saw their faith, he said unto the sick of the palsy, Son, thy sins be forgiven thee. 6 But there were certain of the scribes sitting there, and reasoning in their hearts, 7 Why doth this man thus speak blasphemies? who can forgive sins but God only? 8 And immediately when Jesus perceived in his spirit that they so reasoned within themselves, he said unto them, Why reason ye these things in your hearts? 9 Whether is it easier to say to the sick of the palsy, Thy sins be forgiven thee; or to say, Arise, and take up thy bed, and walk?

If we read Mt 18:18 in context, we realize that Jesus was giving instructions to his disciples (including present day followers -- Christians) that they should not be quick to sue one another in court but rather that they should seek to use the numerous biblical provisions to solve disputes.

Matthew 18
15 Moreover if thy brother shall trespass against thee, go and tell him his fault between thee and him alone: if he shall hear thee, thou hast gained thy brother. 16 But if he will not hear thee, then take with thee one or two more, that in the mouth of two or three witnesses every word may be established. 17 And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican. 18 Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven.

The Seventh Day Adventists actually reference Matt 18:18; in their 28 Fundamental Beliefs:

"The church derives its authority from Christ, who is the incarnate Word, and from the Scriptures, which are the written Word."

The Easy-to-read Version of the bible which you have quoted in your question interprets this verse as referring to forgiveness, that may be what some Christian denominations believe, but others believe this verse refers to authority and priesthood keys. The SDA refer to Matt 18:18 as support for their claim to authority, they believe it applies the the whole church, and not just the leadership.

In regards to forgiveness they have this to say on their website:

Paul wrote, "For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God" (Ephesians 2:8). Please note that word gift. There's no other way to get God's forgiveness than to accept it as a gift! So why suffer? Let God forgive you and lift the weight of guilt from you!

This would imply that they don't believe pastors or ministers can forgive sins, they believe your sins are already forgiven, you just have to accept the gift of God's forgiveness and you shall receive it.

Matthew 18 is used consistently to stress that it is the Church that is given authority, not individuals (see Seventh-Day Adventist Church Manual pg. 31 & 160).

“Again, truly I tell you that if two of you on earth agree about anything you ask for, it will be done for you by my Father in Heaven. For where two or three come together in my name, there am I with them” (Matt 18:19, 20)

As Protestants, the Seventh-Day Adventists are wary of the Church authorities imposing their will upon them. On the other hand they also recognize that the church cannot be lead by individuals who rise up seeking to destroy the established order. They believe there must always be awareness that Jesus is the head of the Church, and that He leads it in the ways He sees fit, placing in leadership those of His own appointment. They believe that their unity is essential for their witness to the world, and becomes a necessary part of the Gospel Commission (see The Role of the Church).

First, Seventh Day Adventists would more likely use the KIng James Version of the verse or an equivalent Bible version that are deemed more tested.

KJV

18 Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven.

This is God's commission to Christians to go into the world and spread the gospel. It highlights the heaviness of responsibility of God's ministers and messengers, as their influence can have a uplifting or detrimental effect to the people. The key here is by faith, if the faith of the disciples are not inline with God's will then heaven will not ratify their actions. This applies to the early apostles and to believers today.

I'll end with some quotes from Ellen White, who is one of our church's main founders, and I can confidently say speaks only according to the Bible. God also gave her visions which we judged and believe is the spirit of prophecy written in Revelation describing the remnant people.

“Verily I say unto you, Whatsoever ye shall bind on earth shall be bound in heaven: and whatsoever ye shall loose on earth shall be loosed in heaven” (Matthew 18:18). When every specification which Christ has given has been carried out in the true, Christian spirit, then, and then only, Heaven ratifies the decision of the church, because its members have the mind of Christ, and do as he would do were he upon the earth.—Letter 1c, 1890

In Christ’s commission to his disciples, he tells them, “Whatsoever ye shall bind on earth shall be bound in heaven; and whatsoever ye shall loose on earth shall be loosed in heaven.” [Matthew 18:18.] If this is the fearfully responsible work of God’s ministers, how important that they give themselves wholly to it, and watch for souls as they that must give an account! Should any separate or selfish interest come in here and divide the heart from the work? — Gospel Worked 1892

The direct answer to your question is that neither an Adventist Pastor nor any of the Apostles have or had the power to forgive sin.

Seventh-day Adventists in common with most Protestant faiths do not practice auricular confession. To God alone is given the right to hear confession and to forgive sin. He is the Great Lawgiver and as David said, "Against you, you only, have I sinned" after his dual sins of adultery and murder. I could add a note about the day of Pentecost but I would but paraphrase John Wycliffe of Oxford University who was the morning star of the Protestant Reformation and renounced the Catholic practice in the 14th Century. In extract he wrote:

"It is not confession to man but to God, who is the true Priest of souls, that is the great need of sinful man. Private confession and the whole system of medieval confession was not ordered by Christ and was not used by the Apostles, for of the three thousand who were turned to Christ's Law on the Day of Pentecost, not one of them was confessed to a priest.... It is God who is the forgiver."

"Faith in our Lord Jesus Christ is sufficient for salvation, and that without faith it is impossible to please God, that the merit of Christ is able, by itself, to redeem all mankind from hell, and that this sufficiency is to be understood without any other cause concurring."

"Trust wholly in Christ, rely altogether on His suffering, beware of seeking to be justified in any other way than by His righteousness. Faith in our Lord Jesus Christ is sufficient for salvation."

"There is no greater heresy for a man than to believe that he is absolved from sin if he gives money, or because a priest lays his hand on his head and says, 'I absolve you;' for you must be sorrowful in your heart, else God does not absolve you."

As you can see it was he who first preached the great Protestant message, 'Justification by Faith and by Faith Alone' which in it's essence is a repudiation of auricular confession.

References:

God's Generals - The Roaring Reformers

Tracts and Treatises of John de Wycliffe

I'm not of the SDA church, but because you ask about SDA opinion specifically. I can tell you adventists cite Mt. 9:3 || Lk. 5:21 to demonstrate that the Catholic Church's claims to forgive sins constitutes "blasphemy":

Jesus. . said to the paralytic, ‘Take heart, son; your sins are forgiven.’ Then some of the scribes said to themselves, ‘This man is blaspheming.’ (Mt. 9:2-3)

Then the scribes and the Pharisees began to question, ‘Who is this who is speaking blasphemies? Who can forgive sins but God alone?’ (Lk. 5:21)