Hi Barely There,
Unfortunately it's always a sticky situation when dealing with anything JW. But as a former elder, I'll give you my views based on experiences while serving on JCs.
While one's sense of justice would say print the emails and expose your ex and his MS pal, don't do it. If you want to get reinstated, don't mention the emails. In most cases the elders will ignore the information, or even worse turn it against you, even though the messages were posted on your email account. In retaliation for exposing one of their own, they could add months to your sentence. As others have advised, don't reveal your hand just yet. Besides your ex may later reveal something really scandalous in the conversations that he posts to your account. This could be valuable once you are reinstated and begin your fade.
Regarding a change of congregations. If your present congregation is too toxic for your spiritual health, it's best that you change to one that is less so. But changing congregations won't necessarily speed or hinder your reinstatement. It all depends on the elders in both congregations.
The elders in your new congregation will need time to evaluate you, which can add more time before reinstatement. Also they can only recommend that you be reinstated, the final decision rests with the JC in your original congregation.
In most cases it will be the same elders who DFd you, who will reinstate you. If you are on good terms with them, there shouldn't be a problem.
Again these are my observations based on my experiences as a former elder. Other ex elders may have better advice. Moreover, the members of this forum have posted a lot of information for you . So don't make any hasty decisions, but take your time and carefully read the posts and see what you are most comfortable with.
Take care,
Athanasius