You have several questions here, I can deal with the Gyn type questions if that suits you..
You can have endometrial ablation more than once, however when it is not successful then many women at your age might choose hysterectomy as an option.
Having laparoscopic surgery when there is previous adhesions and scars may be too difficult as openings need to be created for viewing port as well as the main 'keyhole'.
The risk of further adhesions is increased and this increases risk of pain and slower recovery. Complications depends which type of procedure is carried out but all surgery comes with risk of bleeding, DVT and infection.
I would think it unlikely that your doctor would do both procedures at the same time owing to confusion over any complications and the need to allow time for recovery.
After a bladder sling then hospital stay is usually only a few day but full recovery can take up to 3 months before you can lift heavy objects and be considered 'back to normal', although most people see immediate benefits with their symptoms and quality of life.