Seperation Agreement Questions

What are the advantages and disadvantages of incorperating a seperation agreement into an absolute divorce?

Additionally, my soon to be ex and I are fast approaching our 1 year/1 day seperation requirement and we both want out of this marriage as soon and as painless as possible.

Can I personally serve my STBX or does it have to be by sheriff or certified mail?

What methods are available to speed up the divorce process after the required 1y/1d seperation has passed?

My STBX is buying a house 2 weeks after our seperation requirement has passed AND I’m moving out of state 3 weeks after. If possible,we’d like to get the divorce granted before her buying a home and my relocation.

It really depends on what the terms of the agreement are, I cannot say for sure if you should incorporate an agreement into a divorce decree without reading the agreement and knowing all of the facts.
Essentially the Separation Agreement becomes a court order which is enforceable by contempt. If there are alimony provisions in the agreement, the alimony becomes modifiable based on a showing of a substantial change in circumstances.
Once the divorce complaint is filed your ex will need to be served either via sheriff, or certified mail. You, as a party to the action, cannot serve him.
Even if you file for the divorce now, it is doubtful the process can be completed in 5 weeks, however if your ex remains in NC, there is no issue with having the divorce process completed in NC, as only one party needs to live in state.