Matthew 28 is filled with a ton of stuff. I may have tried to squeeze in too much by making the last chapter one post, we'll see how this one goes.
The SAB has a slew of questions on just the first two verses, so I'm going to list them all here: "How many women went to the sepulchre?" "When did they arrive?" "Whom did they see at the tomb?" "Was the tomb open or closed?" "Were the men or angels inside or outside the tomb when first seen?" Here is my take. A whole bunch of women came to the sepulchre, but they didn't all travel in one group, and in particular, Mary Magdalene was the first to arrive, before dawn, alone. She sees the stone rolled away already, why? Because as it says in verse 2, an angel had come and rolled it back. (Yes, I am suggesting that chronologically, verses 2-4 happened before verse 1, and it's my understanding that the Greek can support that.) The angel that rolled back the stone was seen by the guards outside the tomb, but the angel (or two angels, it's not clear) that spoke to the women was inside the tomb.
"Did the women immediately tell the disciples?" Well, they told them as soon as they found them. I would say that the verse in Mark indicates that they were too afraid to go and tell just anyone, so they stayed silent until they found who they were looking for.
Verse nine gives us a ton of questions again: "To whom did Jesus first appear?" "Did Mary Magdalene recognize Jesus?" "Was it OK to touch the risen Jesus?" "Was Mary Magdalene happy or sad when she saw the risen Jesus?" The question of to whom Jesus first appeared is a tricky one, but the answer is Mary Magdalene. There is a lot of stuff going on that Sunday morning, and in the midst of it, it's easy to miss that as Mark 16:9 says, the story at John 20:11ff is the story of Jesus first appearing to anyone. Although Matthew 28:9 sounds like a first appearance, in John 2:2 we are told that as Mary M. came to the tomb and found it empty, she immediately ran and got Peter and John. While the other women were travelling, Mary came back to the tomb and saw Jesus first. Mary was not with the group of women spoken of in verse 9, and when she saw Jesus, she didn't recognize him at first. While it did seem to be okay to touch the risen Jesus in general, Jesus did for some reason tell Mary M. not to touch him. Whether this was only okay later, or there was something about the way that Mary was touching him (I've heard some suggest that she was clinging to him tightly, and he was telling her that he could not stay) I don't know. Anyway, Mary was indeed sad when she first saw Jesus, but mainly because she didn't recognize him and was still confused.
"Where did Jesus tell his disciples to meet him?" This is simple: He told them to go to Galilee. Once they had gone to Galilee and met with him, he told them to go back to Jerusalem, where they would wait for Pentecost. "How many disciples did Jesus appear to in his first post resurrection appearance?" The linked page might be a problem if any of those verses actually said it was the "first" post resurrection appearance; I'll stick with "One", that being Mary Magdalene. (It's worth noting about the 1Corinthians passage that sometimes the Bible uses the term "the twelve" to refer to the Apostles, even when there were less than twelve present at an event.
"How much power did Jesus have?" I think you have to take into consideration that this is the post resurrection Jesus, and he's more powerful than he was while a mere mortal.
"Should the gospel be preached to everyone?" I thought I had addressed this previously, but not very thoroughly apparently. Yes, the Gospel should be preached to everyone, despite the fact that sometimes the timing is not right to preach to any one particular group.
"In whose name is baptism to be performed?" I don't see a strong reason why it should be one way or the other. That's the end of the book, and I think I'll just let that one drop.