I can talk about chemo/rad, it helped me, most people get down staged, so the operation is possible, than once that is behind, deal with lungs and liver.
Temporary or permanent bag, I wouldnt be vorying about that now, what I can see from posts, permanent bag might be better choice, people that have it complain less, people that have reversal option seem to have far more complains and issuess.
In your husbands case colostomy might not be bad option, it might be hard to deal with reversal at same time, as he will have to deal with lungs and liver.
One problem at time, stay focused and positive, dont read to much into studies, treatments are improving, we might even have vaccine in couple of years, your oncologists look at floor, its not easy job to deliver that kind of news.
Second opinion is good, different eyes see different things, but dont delay treatment, time is critical, cancer is like snow ball.
Just my opinion.
Good luck to your husband and you!
55 year, male, never been seek in my life.
Diagnosed with T1,T2 N0 M0 rectal cancer, tumor 4.5cm,
Discovered by pure lack, after taking baby ASA, had blood in stool.
25 sessions of Chemo/rad finished end of January 2017, focus was on lymph nodes
Tumor erased, CCR, negative mri, ct, scope, no evidence of cancer
April 2017, folfox 8 rounds plus 2 rounds of xeloda
Sept.2017 CT , MRI negative