Were these questions ever answered? (Spoilers)

1. What exactly happened with Garrett and Jenna the night Ali "died"? There was a flashback in season 3 of Garrett preparing to kill Alison, but then he only pretends to in order to make Jenna think he does. Ali seemed to be in on it. Later that night, Mona kills Bethany, thinking it was Ali. Did Mona hire Garrett and Jenna to kill Ali, but then Garrett let Ali know that she was in danger? If he did, you'd think he would let her know about Mona, but then Ali accepts help from her later that night. Also, Mona was helping her after she thought she killed her with a shovel.

2. Another thing about 'that night', it was first established that Cece was wearing the same clothes as Ali. In a later flashback to that same night, we see her wearing the black hoodie 'A' gear. Was this ever followed up on?

3. Another confusing thing is that Cece says that she took over Mona's game when they met in Radley. Yet in the season 2 finale, after Mona's admitted into Radley, she says to another A something like, "I did everything you asked me to do", implying that someone else is pulling the strings.

4. Was it ever clarified if Nate/Lyndon was on the A-team or if he was just a random stalker? I got the impression it was the latter, but those videos of Maya implied she knew something about the whole A fiasco.

5. What was up with those tombstones in Ravenswood? I don't recall them ever addressing it again. It was such an odd thing.

Were these things addressed and I forgot or are they more examples of bad writing?