Do I have visceral fat or diastasis recti after two pregnancies? Would a tummy tuck even help? (photos)

Healthy people at their ideal weight should have the best overall recovery from a TT and lipo, but some of this will depend upon the surgical technique and adherence to postoperative protocols. 
Liposuction, combined with the standard TT, will allow you to have stubborn fat resistant to exercise and diet removed from unwanted areas.  A TT with muscle tightening because of diastasis recti will create a flat abdomen and would also provide the benefit of placing your incision along the lower pubic region. The TT also creates a more youthful belly button. 
If the waist was smaller at one time, the waist can likely be reduced to those same measurements or smaller provided the muscular and fascial integrity has remained the same.
Consult with a board certified PS who has performed hundreds of TTs and liposuction procedures with favorable patient reviews and great results evidenced in before and after photos on his/her website.

Hello! From your photos it appears you indeed have rectus diastasis.  A full tummy tuck with muscle repair and liposuction would benefit you.  However, a tummy tuck and liposuction will not correct visceral fat.  It is best to schedule an in person consultation with a board certified plastic surgeon to determine the best surgical plan for you.  Best of luck!