I totally understand that this can be frustrating when you're not able to edit your post on certain boards or to be specific on this board however, there have been instances back then where people have abused such privileges, till date you might have seen some people are still abusing this features by posting things which they weren't supposed to and later editing their original post to find a way to go away with this (Not possible anymore but still we do see some spam post) and thus, such restrictions have been imposed. However, considering the fact that it has been
suggested in the past by other community members to let our members have permission to edit their posts, I will look into this again and will discuss this with Staff members and Stan and see what can be done here, again, I can't promise If such restrictions will be lifted but I will do my best to look into this.
As to not being able to embed the Facebook video link in this forum, I believe this is a restriction that has been imposed by Facebook however, I will look into that and see If there's a way to by-pass such restriction and be able to embed the links and once I have found the solution, I will edit your original post to make it right.
Update - After doing the necessary research it seems that you might probably have to check your original Facebook post settings to see If there's an option for you to allow others to use your videos or share it and there have been some issue with Xenforo itself to restrict users to post such videos and to fix it, I might have to dig in deeper and make some back end changes but that might take a while.