Big Hugs! I could go on and on about my divorce process, but the circumstances with my Ex sound similar to yours. I was ALWAYS the breadwinner. Ex couldn't / wouldn't keep a job with stable income. He ran up a huge credit card balance and expected me to pay for everything. He didn't want the divorce. Swore he would change. Didn't want "our" son to have divorced parents. He's a great talker and tried to convince me over and over and over again to take him back. I listened politely and then continued with the divorce. It was easier once he moved out.
2.5 years later...
He doesn't pay child support. He doesn't speak to my son. He doesn't buy presents. It's been almost a year since he's seen his kid. Breaks my heart, but I know both of us are in a better place. I honestly don't think many people can truly change.
And yes, lawyers will do online research, etc. during the divorce process. My Ex never retained a lawyer, but I believe he tried to hack into my mobile phone online account and he also installed a computer program that allowed him access while I was online on our home computer. DH's Ex's attorney requested tons of documentation and records trying to get dirt on him during their divorce.
Finally, divorce is indeed a grieving process and people handle it differently. I think by the time the person who wants the divorce actually files, the plaintiff has already started grieving. The defendant is kind of at a disadvantage. My Ex had warnings from me for probably 6 months prior to me filing and still acted like he was shocked and surprised.