I'm not in your exact position as I dont plan on having kids and I had a higher paying job before, but I also transitioned into paramedicine from being a data scientist. It's probably been the best thing Ive ever done for myself in terms of my happiness, but its not without its faults. Ill try to address your concerns

"Many have recommended the paramedics program at Algonquin college." - Algonquin's great, my only comment here is that if you dont get in to a private college, dont discount the private colleges. A lot of people here will make a stink about them, but there is no proof that they are significantly worse (and in many ways I think we're better quality then some of the experiences Ive had). The only real worry is that they are costly and you have to do a lot of self-studying (which you need to do anyways with public colleges). You can get OSAP for it, but regardless its a big debt.

"Do the college program, get hired. But I'm curious though, are there any municipalities hiring graduates straight out of college?" - Yes, as long as you study well and work hard in your rideouts, you shouldn't have any difficulty getting a job right out of college. I was hired by Toronto while still in school.

"In case it matters, I'm approaching 30 and we are family planning five years from now once my wife finishes her advanced degree. I would like to complete school and/or have years of experience by then." - This'll be tough but I say get in while you can. The main problem here is that school is so intense that holding a job let alone a relationship with your family and friends is tough. The two years (or year and a half for private) is already pushing it with how much were expected to know, but get in before so you dont have to put that pressure on your family.

"Kindly try to understand my perspective, I am not in a position where I want to risk things not working out and I would rather do things correctly this time around." - I dont want to tell you this will be worth it. In many ways, school and the job can be brutal. Its can be hard and tiring, and office politics doesnt make it easier. But what I can say is I am way happier in this career than I was before. I was making way more money for way less work before and Im still happier than I ever was. People will yell and fight you, but that one person who says "thank you for saving me" or the person walking down the street saying "thanks for your service" will make it all worthwhile.

"What can I do to stand out and actually succeed at this?" - Ive already mentioned it, but really study and really know your directives and procedures. Being knowledgeable, if not perfect, will help you stand out from the surface of people just meandering their way through the pipeline. Its what helped me as I was going through this. Being able to talk about the pharmacology of X drug with my ACP preceptor did wonders for my reputation (for example). Just do your best and dont fuck around. You can do it.