Yes....... as long as you know what the issues were before and are concious about working on them in the future so you don't fall into old routines.....
hmmmmm now.. get back together as in together I don't know.. there would have had to be a reason to go back.. however hooking up with an ex even though sometimes can be a mistake.. at least it's familiar...lol...
Not without resolving the issues that made them an ex to begin with. As they say, doing the same thing over and over again and expecting different results is a sign of insanity.