Can I counter for harassment for him trying to sue me for things I didn't do?
Yes, you can countersue for harassment or for sanctions for a frivolous lawsuit.
Are there any options against him since he lied on my unemployment application to try and keep me from receiving benefits?
There's not much you can do about the unemployment benefits although it could be perjury or falsifying a government document, depending on exactly how it happened. However, this is a charge that the State has to pursue.
Wasn't the summons supposed to include all details?
The summons itself doesn't but the complaint/petition has to allege sufficient facts to "state a case". If you need addition facts then you file a motion with the court, such as a Special Exception, asking the court to require them to plead more specifically.
They speak about a supposed email but did not include it like they included the rating on the healthcare website?
There is no requirement that they include the email but you can get it using the discovery process.
What are my chance of being sued?
I'm not sure what you mean by this since you have already been sued.
Is his lies to unemployment considered malefic?
Malefic is not a legal term and the common definition means it involves the supernatural, so no. If you mean were his statements done in bad faith, that's not really something I can address since I can't do a complete evaluation of all of the facts, documents, witnesses, etc. However, it doesn't make a huge difference in the lawsuit itself since that issue has to be handled through the unemployment process and not the lawsuit in which you are engaged.